Mercury MerCruiser MCM 454 Mag MPI Service Manual
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Mercury MerCruiser MCM 454 Mag MPI Service Manual

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Table of Contents

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MAIN MENU
SERVICE
MANUAL
Number 23
MARINE ENGINES
GM V8 454 cid (7.4L) / 502 cid (8.2L)
Book 1 of 2
Sections 1 thru 4
1999, Mercury Marine
Printed in U.S.A.
90-861326--1 MARCH 1999
Downloaded from
https://needmanual.com/

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Summary of Contents for Mercury MerCruiser MCM 454 Mag MPI

  • Page 1 MAIN MENU SERVICE MANUAL Number 23 MARINE ENGINES GM V8 454 cid (7.4L) / 502 cid (8.2L) Book 1 of 2 Sections 1 thru 4 1999, Mercury Marine Printed in U.S.A. 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 2 Mercury Marine, that they have been trained in the recommended servicing procedures of these products which in- cludes the use of mechanics’ common hand tools and the special Mercury Marine or recom- mended tools from other suppliers.
  • Page 3 It is important to note, during any maintenance procedure replacement fasteners must have the same measurements and strength as those removed. Numbers on the heads of the met- ric bolts and on the surfaces of metric nuts indicate their strength. American bolts use radial lines for this purpose, while most American nuts do not have strength markings.
  • Page 4 Models Covered in This Manual Gen. VI Engines Sterndrive (MCM) Model Serial Number MCM 454 Mag MPI 0L010029 & Up MCM 502 Mag MPI 0L017000 & Up Inboard (MIE) Model Serial Number MIE 454 Mag MPI Horizon 0L002200 & Up MIE 8.2L MPI 0L002450 &...
  • Page 5 THIS PAGE IS INTENTIONALLY BLANK Page iv 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 6 NOTE:Outline contains book 1 and 2 Service Manual Outline Important Information Section 1 - Important Information A - General Information B - Maintenance C - Troubleshooting Removal And Installation Section 2 - Removal and Installation A - MCM Models - Bravo and Blackhawk Drives B - MCM Models - Bravo and Blackhawk Drives with Engine Driveshaft Extension...
  • Page 7 THIS PAGE IS INTENTIONALLY BLANK Page vi 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...

  • Page 8: Table Of Contents

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 IMPORTANT INFORMATION Section 1A - General Information Table of Contents Introduction ......1A-2 Water Testing New Engines .

  • Page 9: Introduction

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 Introduction This comprehensive overhaul and repair manual is designed as a service guide for the models previously listed. It provides specific information, including procedures for disassembly, inspection, assembly and adjustment to enable dealers and service mechanics to repair and tune these engines.

  • Page 10: How To Read A Parts Manual

    CABLE TIE REF. NO. : Number shown next to part on exploded view PART NO. : Mercury Part Number for ordering. If NSS (not sold separately) sometimes GM part number will be given in description column. QTY. : The quantity that must be ordered.

  • Page 11: Directional References

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 Directional References Front of boat is bow; rear is stern. Starboard side is right side; port side is left side. In this service manual, all directional references are given as they appear when viewing boat from stern looking toward bow.

  • Page 12: Engine Serial Number Locations

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 Engine Serial Number Locations 72923 Stern Drive (MCM) Serial Number Plate Starter Motor 72924 Inboard (MIE) Serial Number Plate Starter Motor Index Index 90-861326--1 MARCH 1999 Page 1A-5 Downloaded from https://needmanual.com/...

  • Page 13: Propeller Information

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 Propeller Information Refer to the “Propeller” section in appropriate MerCruiser Sterndrive Service Manual, or order publication 90-86144-92, “Everything you need to know about propellers.” Changing diameter, pitch or coupling of a propeller will affect engine rpm and boat perfor- mance.

  • Page 14: Boat And Engine Performance

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 Boat and Engine Performance Boat Bottom For maximum speed, a boat bottom should be as flat as possible in a fore-aft direction (longitudinally) for approximately the last 5 ft (1.5 m). 72002 Critical Bottom Area For best speed and minimum spray, the corner between the bottom and the transom should be sharp.

  • Page 15: Marine Fouling

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 A “rocker” is the reverse of a hook. The bottom is convex or bulged in the fore-and-aft direc- tion. It can cause the boat to porpoise. 72005 Rocker Transom (Stern) Any hook, rocker or surface roughness on the bottom, particularly in the critical center-aft portion will have a negative effect on speed, often several miles per hour on a fast boat.

  • Page 16: Weight Distribution

    GENERAL INFORMATION SERVICE MANUAL NUMBER 23 Weight Distribution Weight distribution is extremely important; it affects a boat’s running angle or attitude. For best top speed, all movable weight - cargo and passengers - should be as far aft as possible to allow the bow to come up to a more efficient angle (3 to 5 degrees).
  • Page 17 GENERAL INFORMATION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Index Page 1A-10 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 18 MAINTENANCE SERVICE MANUAL NUMBER 23 IMPORTANT INFORMATION Section 1B - Maintenance Table of Contents Lubricants / Sealants / Adhesives ..1B-2 Changing Water Separating Fuel Filter 1B-19 Maintenance Schedules ....1B-3 MCM (Sterndrive) Models .

  • Page 19: Lubricants / Sealants / Adhesives

    MAINTENANCE SERVICE MANUAL NUMBER 23 Lubricants / Sealants / Adhesives DESCRIPTION PART NUMBER Quicksilver Liquid Neoprene 92-25711--3 Quicksilver 2-4-C Marine Lubricant With 92-825407A3 Teflon Loctite Pipe Sealant With Teflon Obtain Locally Quicksilver U-Joint and Gimbal Bearing 92-828052A2 Grease Index Index Page 1B-2 90-861326--1 MARCH 1999 Downloaded from...

  • Page 20: Maintenance Schedules

    MAINTENANCE SERVICE MANUAL NUMBER 23 Maintenance Schedules Maintenance Intervals Maintenance intervals and the tasks to be performed, as shown in this current schedule, or as found in a previously printed schedules, are generally based on an average boating application and environment. However, individual operating habits and personal mainte- nance preferences can have an impact on the suggested intervals.

  • Page 21: Scheduled Maintenance That Should Be Done By Dealer

    MAINTENANCE SERVICE MANUAL NUMBER 23 Scheduled Maintenance That Should Be Done by Dealer NON-HORIZON MODELS NOTE: Only perform maintenance which applies to your particular power package. Task Interval Whenever Insufficient Seawater Flow Is Seawater Pickup Pump - Disassemble Suspected. (If Operating Temperature And Inspect Exceeds Normal Range.) Crankcase Oil and Filter - Change...

  • Page 22: Scheduled Maintenance That Should Be Done By Dealer

    MAINTENANCE SERVICE MANUAL NUMBER 23 Scheduled Maintenance That Should Be Done by Dealer NON-HORIZON MODELS NOTE: Only perform maintenance which applies to your particular power package. Task Interval Steering Head and Remote Control - End Of First Boating Season And Inspect And Lubricate Thereafter, Every 100 Hours Of Operation Or Once Yearly, Whichever Occurs First...

  • Page 23: Scheduled Maintenance That Can Be Performed By An Owner/Operator

    MAINTENANCE SERVICE MANUAL NUMBER 23 Scheduled Maintenance That Can Be Performed By An Owner/Operator HORIZON MODELS Recommended Maintenance Interval Engine Oil - Check Level Transmission Fluid - Check Level Before Every Use Closed Cooling - Check Level Power Package Surfaces - Spray with Saltwater Use: Yearly Quicksilver Corrosion Guard Scheduled Maintenance That Should Be Done by Dealer...
  • Page 24 MAINTENANCE SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Index 90-861326--1 MARCH 1999 Page 1B-7 Downloaded from https://needmanual.com/...
  • Page 25 MAINTENANCE SERVICE MANUAL NUMBER 23 Tune-Up Specifications MCM (Sterndrive) Models MCM 454 Mag MCM 502 Mag Model MCM 7.4L MPI Propshaft Horsepower (SAV1 Rating) (275 Propshaft Kilowatts (SAV1 Rating) (205 Number of Cylinders 502 C.I.D. Displacement 454 C.I.D (7.4L) (8.2L) 4.47 x 4.00 Bore/Stroke In.
  • Page 26 MAINTENANCE SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Index 90-861326--1 MARCH 1999 Page 1B-9 Downloaded from https://needmanual.com/...
  • Page 27 MAINTENANCE SERVICE MANUAL NUMBER 23 MIE (Inboard) Models MIE 454 Mag Model MIE 7.4L MPI MIE 8.2L MPI MPI Horizon Propshaft Horsepower (SAV1 Rating) (275 Propshaft Kilowatts (SAV1 Rating) (205 Number of Cylinders 502 C.I.D. Displacement 454 C.I.D (7.4L) (8.2L) 4.47 x 4.00 Bore/Stroke In.

  • Page 28: Firing Order

    MAINTENANCE SERVICE MANUAL NUMBER 23 Firing Order 72008 LH ROTATION FRONT FIRING ORDER 1-8-4-3-6-5-7-2 Fluid Capacities Engines NOTICE Unit Of Measurement: U.S. Quarts (Liters) All capacities are approximate fluid measures. MCM AND MIE MCM AND MIE MODEL 454 cid / 7.4L 502 cid / 8.2L Crankcase Oil (With Filter)

  • Page 29: Transmissions

    MAINTENANCE SERVICE MANUAL NUMBER 23 Transmissions NOTICE Unit Of Measurement: U.S. Quarts (Liters) All capacities are approximate fluid measures. CAPACITY MAKE AND MODEL FLUID TYPE QUARTS (LITERS) Velvet Drive 72C In-Line 1.5 (1.3) 5000A Dexron III Automatic 3 (2 75) 3 (2.75) Transmission Fluid 5000V...

  • Page 30: After Break-In Period

    MAINTENANCE SERVICE MANUAL NUMBER 23 After Break-in Period To help extend the life of your MerCruiser power package, the following recommendations should be considered; Use a propeller that allows the engine to operate at or near the top of the maximum rpm range (See “Specifications”...

  • Page 31: Specifications

    MAINTENANCE SERVICE MANUAL NUMBER 23 CA261 Specifications Fuel Recommendations IMPORTANT: Use of improper gasoline can damage your engine seriously. Engine damage resulting from use of improper gasoline is considered misuse of engine, and damage caused thereby will not be covered under the limited warranty. FUEL RATINGS MerCruiser engines will operate satisfactorily when using a major brand of unleaded gaso- line as follows:...

  • Page 32: Test For Alcohol Content In Gasoline

    MAINTENANCE SERVICE MANUAL NUMBER 23 WARNING FIRE AND EXPLOSION HAZARD: Fuel leakage from any part of fuel system can be a fire and explosion hazard which can cause serious bodily injury or death. Careful periodic inspection of entire fuel system is mandatory, particularly after storage. All fuel components including fuel tanks, whether plastic metal or fiberglass, fuel lines, fittings, fuel filters and carburetors/fuel injection components should be in- spected for leakage, softening, hardening, swelling or corrosion.

  • Page 33: Coolant For Closed Cooling System

    MAINTENANCE SERVICE MANUAL NUMBER 23 Coolant for Closed Cooling System CAUTION Alcohol or Methanol base antifreeze or plain water, are not recommended for use in fresh water section of cooling system at any time. We recommend that the coolant section of closed cooling system be filled with Extended Life Ethylene Glycol 5/100 Antifreeze/Coolant mixed 50/50 with purified water.

  • Page 34: Overfilled Crankcase

    MAINTENANCE SERVICE MANUAL NUMBER 23 Overfilled Crankcase Overfilled crankcases (oil level being too high) can cause a fluctuation or drop in oil pressure and rocker arm “clatter” on MerCruiser engines. The over-full condition results in the engine crankshaft splashing and agitating the oil, causing it to foam (become aerated). The aerated oil causes the hydraulic valve lifters to “bleed down.”...

  • Page 35: Changing Oil And Filter

    MAINTENANCE SERVICE MANUAL NUMBER 23 7. Remove oil filler cap from valve rocker arm cover. 75988 Oil Cap 8. Add required amount of oil to bring level up to, but not over the FULL mark on dipstick. Changing Oil and Filter 1.

  • Page 36: Changing Water Separating Fuel Filter

    MAINTENANCE SERVICE MANUAL NUMBER 23 Changing Water Separating Fuel Filter WARNING Be careful when changing water separating fuel filter. Gasoline is extremely flammable and highly explosive under certain conditions. Be sure ignition key is OFF. Do not smoke or allow spark or open flame in area when changing fuel filter. Wipe up any spilled fuel immediately.

  • Page 37: Mie (Inboard) Models

    MAINTENANCE SERVICE MANUAL NUMBER 23 2. Remove water separating fuel filter and sealing ring from mounting bracket and discard. 70573 Fuel Filter Sealing Ring 3. Coat sealing ring on new filter with motor oil. Thread filter onto bracket and tighten securely by hand.

  • Page 38: Power Steering System

    MAINTENANCE SERVICE MANUAL NUMBER 23 Power Steering System Checking Fluid Level ENGINE WARM 1. Stop engine and position drive unit so that it is straight back. 2. Remove fill cap/dipstick from power steering pump and note fluid level. 75484 Fill Cap / Dipstick Power Steering Pump 3.

  • Page 39: Filling And Bleeding

    MAINTENANCE SERVICE MANUAL NUMBER 23 ENGINE COLD 1. With engine stopped, position drive unit so that it is straight back. 2. Remove fill cap/dipstick from power steering pump and note fluid level. 3. Level should be between FULL COLD mark and bottom of dipstick. 72519 Proper Fluid Level with Engine Cold 4.

  • Page 40: Closed Cooling System

    MAINTENANCE SERVICE MANUAL NUMBER 23 5. Position drive unit so that it is straight back and stop engine. Remove fill cap from pump. Allow any foam in pump reservoir to disperse, then check fluid level and add fluid, as required, to bring level up to FULL HOT mark on dipstick. DO NOT OVERFILL. Reinstall fill cap securely.

  • Page 41: Flushing System Mcm (Sterndrive)

    MAINTENANCE SERVICE MANUAL NUMBER 23 Flushing System MCM (Sterndrive) If engine is operated in salty, polluted or mineral-laden water, flush cooling system (prefer- ably after each use) to reduce corrosion and prevent the accumulation of deposits in the system. Thoroughly flush cooling system prior to storage. NOTE: For additional protection against freezing and rust to the exhaust manifolds and other components, a 50-50 mixture of antifreeze and water can be run through the engine during Power Package Layup.
  • Page 42 MAINTENANCE SERVICE MANUAL NUMBER 23 BOAT IN WATER 1. Raise drive unit to full UP position. 2. Install flushing attachment over water pickup holes in gear housing as shown. 3. Attach a hose between the flushing attachment and a water tap. 72693 Flushing Attachment Hose...

  • Page 43: Flushing System Mie (Inboard) - Except 454 Mag Mpi Horizon

    MAINTENANCE SERVICE MANUAL NUMBER 23 Flushing System MIE (Inboard) - Except 454 Mag MPI Horizon CAUTION If boat is in the water, seacock, if so equipped, must remain closed until engine is to be re-started, to prevent water from flowing back into cooling system and/or boat. If boat is not fitted with a seacock, water inlet hose must remain disconnected and plugged (to prevent water from flowing back into cooling system and/or boat).
  • Page 44 MAINTENANCE SERVICE MANUAL NUMBER 23 WARNING When flushing, be certain the area around propeller is clear, and no one is standing nearby. To avoid possible injury, remove propeller. CAUTION Do not run engine above 1500 rpm when flushing. Suction created by seawater pick- up pump may collapse flushing hose, causing engine to overheat.

  • Page 45: Flushing System Mie (Inboard) 454 Mag Mpi Horizon

    MAINTENANCE SERVICE MANUAL NUMBER 23 Flushing System MIE (Inboard) 454 Mag MPI Horizon EARLY MODEL FLUSHING SYSTEM NOTE: This system has a black hose connecting the hose fitting to the flush valve. CAUTION Do NOT start engine at any point in this procedure. If boat is in the water, starting engine during this procedure will pull in seawater.
  • Page 46 MAINTENANCE SERVICE MANUAL NUMBER 23 3. Turn on water to highest pressure. 4. Attach flush socket to engine flush valve on exhaust elbow. 5. Allow engine to flush for 5 minutes. 6. Attach to next engine, if equipped, and repeat procedure. 7.
  • Page 47 MAINTENANCE SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Index Page 1B-30 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 48 MAINTENANCE SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Index 90-861326--1 MARCH 1999 Page 1B-31 Downloaded from https://needmanual.com/...

  • Page 49: Transmission Fluid

    MAINTENANCE SERVICE MANUAL NUMBER 23 Transmission Fluid Checking Fluid Level NOTE: Due to the various installation angles and oil cooler set-ups, it may be necessary to adjust oil level. WARNING Do not remove dipstick with engine running. Hot oil can cause burns. CAUTION Clean around the area of the dipstick before removing.

  • Page 50: Lubrication

    MAINTENANCE SERVICE MANUAL NUMBER 23 TRANSMISSION COLD NOTE: For ease of checking the oil prior to engine start-up, a cold oil level mark can be made. To find the cold oil level mark, the oil level must first be set according to the warm oil level checking procedure.

  • Page 51: Shift Cable

    MAINTENANCE SERVICE MANUAL NUMBER 23 Shift Cable MCM MODELS 72016 Typical Shift Cable Pivot Points Guide Contact Surface Shift Cable and Transmission Linkage MIE MODELS 72528 Typical Shift Cable And Transmission Linkage Pivot Points Guide Contact Surface Index Index Page 1B-34 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...

  • Page 52: Engine Coupler / U-Joint Shaft Splines

    MAINTENANCE SERVICE MANUAL NUMBER 23 Engine Coupler / U-Joint Shaft Splines MCM MODELS NOTE: Engine coupler and shaft splines are greased with Quicksilver Engine Coupler Spline Grease, 92-816391A4; universal joints are greased with Quicksilver 2-4-C Marine Lubricant. NOTE: Refer to MerCruiser Sterndrive Service Manual for sterndrive unit removal and installation, if necessary.

  • Page 53: Drive Shaft Extension Models

    MAINTENANCE SERVICE MANUAL NUMBER 23 Drive Shaft Extension Models 72018 Bearings at Transom End Lubrication Points 72028 Bearings at Engine End Lubrication Points Index Index Page 1B-36 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...

  • Page 54: Starter Motor

    MAINTENANCE SERVICE MANUAL NUMBER 23 Starter Motor MIE MODELS WARNING When performing the following procedure, be sure to observe the following: Be sure that engine compartment is well ventilated and that no gasoline vapors are present to avoid the possibility of a fire. Be sure to ground coil high-tension wire to block.

  • Page 55: Cleaning Flame Arrestor

    MAINTENANCE SERVICE MANUAL NUMBER 23 Cleaning Flame Arrestor WARNING Avoid gasoline fire or explosion. Gasoline is extremely flammable and highly explosive under certain conditions. Be careful when cleaning flame arrestor and crankcase ventilation hoses. Be sure that ignition is OFF. DO NOT smoke or allow sources of spark or open flame in area when cleaning flame arrestor and crankcase ventilation hoses.

  • Page 56: Plastic Front Mounted Flame Arrestor 1B-39

    MAINTENANCE SERVICE MANUAL NUMBER 23 Plastic Front Mounted Flame Arrestor 1. Remove starboard side engine cover. 2. Loosen clamp. 3. Remove flame arrestor. 75447 Cover Clamp Flame Arrestor 4. Clean flame arrestor in solvent. Blow dry with compressed air. 5. Reinstall flame arrestor. Tighten clamp securely. 6.

  • Page 57: Serpentine Drive Belt

    MAINTENANCE SERVICE MANUAL NUMBER 23 3. Remove flame arrestor. 4. Clean flame arrestor in solvent. Blow dry with compressed air. 5. Clean crankcase ventilation hoses in solvent. Blow dry with compressed air. 6. Inspect crankcase ventilation hoses for cracks or deterioration, and replace if necessary.
  • Page 58 MAINTENANCE SERVICE MANUAL NUMBER 23 NOTE: Some models will have components arranged in a different order. All configurations are not shown. Checking, replacing and adjustment procedures are the same. 75424 Inboard Model Idler Pulley Seawater Pump Pulley Crankshaft Pulley Circulating Pump Pulley Alternator Pulley 75487 Sterndrive Model...

  • Page 59: Inspecting

    MAINTENANCE SERVICE MANUAL NUMBER 23 Inspecting 1. Inspect drive belt for the following: Excessive wear Cracks NOTE: Minor, transverse cracks (across the belt width) may be acceptable. Longitudinal cracks (in direction of belt length) that join transverse cracks are NOT acceptable. Fraying Glazed surfaces 75130...

  • Page 60: Ignition Timing

    MAINTENANCE SERVICE MANUAL NUMBER 23 Ignition Timing Two items of test equipment are required: an inductive pickup timing light and a Scan Tool. 1. Connect timing light (91-99379 or similar) to No. 1 spark plug wire. Connect power supply leads, if applicable, on light to 12 volt battery. Refer to Specifications - “Engine Rotation and Firing Order,”...

  • Page 61: Cold Weather Or Extended Storage

    MAINTENANCE SERVICE MANUAL NUMBER 23 10. Manually close the throttle to bring engine rpm back to idle. IMPORTANT: Set the tool to NORMAL MODE before attempting to resume normal op- erations. If the setting of the tool remains in SERVICE MODE, the ignition system will operate only in the “Service Mode.”...

  • Page 62: Power Package Layup

    MAINTENANCE SERVICE MANUAL NUMBER 23 IMPORTANT: To prevent threads in manifolds, elbows and cylinder blocks from rust- ing out during storage, reinstall plugs using Quicksilver Perfect Seal (92-34227--1) on threads. Never leave drain plugs out during storage. CAUTION Sterndrive unit should be stored in full “down” position. Universal Joint bellows may develop a “set”...
  • Page 63 MAINTENANCE SERVICE MANUAL NUMBER 23 7. Prepare fuel system for extended storage as follows: a. Allow engine to cool down. b. Remove the water separating fuel filter. c. Pour out a small amount of fuel into a suitable container, then add approximately 2 fluid ounces (60 ml) of Quicksilver 2-Cycle Outboard Oil to fuel in the water separat- ing fuel filter.
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  • Page 65 MAINTENANCE SERVICE MANUAL NUMBER 23 Draining Instructions DRAINING SEAWATER (RAW-WATER) COOLED MODELS NOTICE Refer to “Cold Weather or Extended Storage,” “Precautions,” in this section, BEFORE proceeding. MCM (Sterndrive) Models: 1. Engine must be as level as possible to ensure complete draining of cooling system. 2.
  • Page 66 MAINTENANCE SERVICE MANUAL NUMBER 23 6. Remove the engine water circulating pump hose as shown. 72587 Hose, Water Circulating Pump To Thermostat Housing 7. Remove the drain plug from the fuel cooler. 75081 Drain Plug 8. Remove both hoses from seawater pump. 75533 Seawater Inlet Hose Hose To Cooler...
  • Page 67 MAINTENANCE SERVICE MANUAL NUMBER 23 9. Insert a small wire (repeatedly) to make sure that speedometer pitot tube, anode cavity vent hole, and anode cavity drain passage are unobstructed and drained. 71217 Typical Bravo Drive Unit Speedometer Pitot Tube Anode Cavity Vent Hole Anode Cavity Drain Passage 10.
  • Page 68 MAINTENANCE SERVICE MANUAL NUMBER 23 MIE (Inboard) Models: NOTICE Refer to “Cold Weather or Extended Storage,” “Precautions,” in this section, BEFORE proceeding. 1. Engine must be as level as possible to ensure complete draining of cooling system. 2. Remove drain plugs (port and starboard) from cylinder block. 75481 74130 Starboard Side Shown (Port Similar)
  • Page 69 MAINTENANCE SERVICE MANUAL NUMBER 23 4. Repeatedly clean out drain holes using a stiff piece of wire. Do this until entire system is drained. 5. Remove the engine water circulating pump hose as shown. 72587 Hose, Water Circulating Pump To Thermostat Housing 6.
  • Page 70 MAINTENANCE SERVICE MANUAL NUMBER 23 8. On Horizon Model: Remove drain plugs from fittings on each seawater pump hose. 75536 Drain Plugs - One Is Hidden From View 9. Crank engine over slightly with starter motor to purge any water trapped in seawater pickup pump.
  • Page 71 MAINTENANCE SERVICE MANUAL NUMBER 23 DRAINING CLOSED COOLING (COOLANT) MODELS NOTE: All factory installed closed cooling systems come filled with DexCool Extended Life Coolant. This antifreeze requires draining and replacing every five years. The color of this antifreeze is orange. For best results any “top-off” fluid used should be DexCool Extended Life Coolant.
  • Page 72 MAINTENANCE SERVICE MANUAL NUMBER 23 MCM (Sterndrive) Models: NOTICE Refer to “Cold Weather or Extended Storage,” “Precautions,” in this section, BEFORE proceeding. 1. Engine must be as level as possible to ensure complete draining of cooling system. 2. Remove end caps, sealing washers and gaskets from the heat exchanger. 71515 Heat Exchanger Sealing Washer...
  • Page 73 MAINTENANCE SERVICE MANUAL NUMBER 23 4. Remove the drain plug from the fuel cooler. 75081 Drain Plug 5. Repeatedly clean out drain holes using a stiff piece of wire. Do this until entire system is drained. 6. Remove both hoses from seawater pump. 75533 Seawater Inlet Hose Hose To Cooler...
  • Page 74 MAINTENANCE SERVICE MANUAL NUMBER 23 7. Insert a small wire (repeatedly) to make sure that speedometer pitot tube, trim tab cavity vent hole, and trim tab cavity drain passage are unobstructed and drained. 71217 Typical Bravo Drive Unit Speedometer Pitot Tube Anode Cavity Vent Hole Anode Cavity Drain Passage 8.
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  • Page 77 MAINTENANCE SERVICE MANUAL NUMBER 23 MIE (Inboard) Models NOTICE Refer to “Cold Weather or Extended Storage,” “Precautions,” in this section, BEFORE proceeding. 1. Ensure that the boat is as level as possible to ensure complete draining of cooling system. 2. Remove end caps, sealing washers and gaskets from the heat exchanger. 71515 Heat Exchanger Sealing Washer...
  • Page 78 MAINTENANCE SERVICE MANUAL NUMBER 23 4. Remove drain plug from the fuel cooler. 74130 Drain Plug 5. On All Models Except Horizon: Remove both hoses from seawater pump. 75533 Seawater Inlet Hose Hose To Cooler 6. On Horizon Model: Remove drain plugs from fittings on each seawater pump hose. 75536 Drain Plugs - One Is Hidden From View 7.
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  • Page 81 MAINTENANCE SERVICE MANUAL NUMBER 23 Recommissioning NOTICE Refer to “Cold Weather or Extended Storage,” “Precautions,” in this section, BEFORE proceeding. 1. Check that all cooling system hoses are connected and tight and all petcocks and drain plugs are installed and tight. 2.
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  • Page 84 TROUBLESHOOTING SERVICE MANUAL NUMBER 23 IMPORTANT INFORMATION Section 1C - Troubleshooting Table of Contents Precautions ......1C-2 Engine Runs Poorly at Idle .

  • Page 85: Precautions

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Precautions WARNING Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion. WARNING Be careful when cleaning flame arrestor and crankcase ventilation hose; gasoline is extremely flammable and highly explosive under certain conditions. Be sure that ignition key is OFF.

  • Page 86: Used Spark Plug Analysis

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 CAUTION DO NOT run engine above 1500 rpm, as suction created by seawater pickup pump may collapse water supply hose and cause engine to overheat. WARNING Be sure that engine compartment is well ventilated and that no gasoline vapors are present to prevent the possibility of a FIRE or EXPLOSION.

  • Page 87: Spark Plug Analysis

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Spark Plug Analysis Normal Condition Few deposits are present and probably will be light tan or gray in color. This plug shows that plug heat range is compatible with engine, and engine is electrically and mechanically in good running condition.

  • Page 88: Cold Fouling

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Cold Fouling Dry, black deposits indicate rich fuel mixture or weak ignition. Clogged flame arrestor or weak ignition components all are probable causes. If, however, only one or two plugs in set are fouled, check for sticking valves or bad ignition leads. After correcting cause, service (clean, file and re-gap) plugs and reinstall.

  • Page 89: Scavenger Deposits

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Scavenger Deposits Powdery white or yellow deposits are built up on shell, insulator and electrodes. This is normal appearance with certain branded fuels. Accumulation on ground electrodes and shell areas may be unusually heavy, but may be easily chipped off. Plugs can be serviced (clean, file and re-gap) and reinstalled.

  • Page 90: Splashed Deposits

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Splashed Deposits Spotted deposits, which sometimes occur after long delayed tune-up, accumulate after a long period of misfiring. When normal combustion temperatures are restored, upon installation of new plugs, deposits loosen from top of piston and head and are thrown against hot insulator.

  • Page 91: Poor Boat Performance And/Or Poor Maneuverability

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Poor Boat Performance and/or Poor Maneuverability Symptom Cause A. Improper drive unit trim angle B. Improper weight distribution C. Boat is underpowered D. Permanent or power hook in boat bot- Bow too low E. False bottom full of water F.

  • Page 92: Improper Full Throttle Engine Rpm

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Improper Full Throttle Engine RPM RPM Too High Cause Special Information Damaged; pitch too low; diameter too Propeller small; propeller hub slipping. Water pickup or through hull fittings mounted too close to propeller (ventilation); keel located too close to Boat propeller and/or too deep in the water (ventilation).

  • Page 93: Engine Cranks Over But Will Not Start Or Starts Hard

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Engine Cranks Over But Will Not Start Or Starts Hard Important Information 1. First, determine which engine system is causing the problem. To make an engine run, basic components - fuel, spark (ignition), and compression - are required. If all three components are present, the engine should run.

  • Page 94: Engine Will Not Crank Over

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Engine Will Not Crank Over Cause Special Information Remote control lever not in neutral posi- tion Battery charge low; damaged wiring; loose electrical connections Circuit breaker tripped Blown fuse Ignition switch Slave solenoid Faulty neutral start safety switch Open circuit Starter solenoid Starter motor...

  • Page 95: Noisy Alternator

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Noisy Alternator Cause Special Information Loose mounting bolts Drive belt Worn, frayed, loose Loose drive pulley Worn or dirty bearings Faulty diode trio or stator Instrumentation Malfunction Cause Special Information Faulty wiring, loose or corroded terminals Faulty key switch Test, as outlined in SECTION 4D Faulty gauge...

  • Page 96: Poor Fuel Economy

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Poor Fuel Economy Cause Special Information Fuel leaks Prolonged idling; slow acceleration; failure to cut back on throttle once boat is on Operator habits plane; boat overloaded; uneven weight distribution Bent, damaged, or wrong propeller. Water Engine laboring test boat for proper operating rpm at wide- open-throttle...

  • Page 97: Engine Runs Poorly At High Rpm

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Engine Runs Poorly At High RPM Cause Special Information Also refer to “Poor Boat Performance” Crankcase overfilled with oil Check oil level with boat at rest in the water. Anti-siphon valve (if equipped) Restricting fuel supply Plugged fuel tank vent Fuel supply Refer to “Fuel Injection Troubleshooting,”...

  • Page 98: Troubleshooting With Vacuum Gauge

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Troubleshooting with Vacuum Gauge Reading Cause Steady reading between 15-21 inches at Normal idle rpm Extremely low reading, but steady at idle Vacuum leak; incorrect timing; underpowered boat; faulty boat bottom Fluctuates between high and low at idle Blown head gasket between two adjacent cylinders Fluctuates 4 or 5 inches very slowly at idle...

  • Page 99: Valve Cover Area

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Valve Cover Area Location Possible Causes Rocker arm striking valve cover Rocker arm out of adjustment Valve cover area, timed to one-half engine speed, noise could be confined to one ld b Worn rocker arm cylinder or may be found in any multitude of cylinders Bent push rod...

  • Page 100: Camshaft Area

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Camshaft Area Location Possible Causes Crankshaft timing sprocket Timing chain Camshaft area, front of engine, timed to one half engine speed Valve Lifter Cam Bearings Fuel Pump Camshaft area, center of engine, timed to h ft Valve Lifter one half engine speed Cam bearing...

  • Page 101: Miscellaneous

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Miscellaneous Noise Possible Cause Advanced timing Low octane fuel Engine spark knock Engine s ark knock Engine running hot Carbon deposits in engine Vacuum leak Leaking exhaust (manifolds or pipes) Hissing Hissing Loose cylinder heads Blown head gasket Vacuum leak Whistle...

  • Page 102: Oil Pressure

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Oil Pressure Miscellaneous Cause Special Information Use a good automotive oil pressure test Measuring oil pressure gauge. Do not rely on the oil pressure gauge in the boat. Check engine oil level with boat at rest in Oil level should be between the ADD and the water FULL marks...

  • Page 103: Low Oil Pressure

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Low Oil Pressure Cause Special Information Low oil level in crankcase Verify with an automotive test gauge. Defective oil pressure gauge and/or Refer to SECTION 4D for instrument sender testing. Oil broken down; contains water or gas; wrong viscosity;...

  • Page 104: Excessive Oil Consumption

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Excessive Oil Consumption Cause Special Information One quart of oil consumed in 5-15 hours Normal consumption. of operation at wide-open-throttle (espe- cially in a new or rebuilt engine) is normal Clean bilge, run engine with clean white Oil leaks paper on bilge floor, locate oil leak(s) Oil too thin...

  • Page 105: Water In Engine

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Water In Engine Important Information IMPORTANT: First determine location of water in engine. This information can be of great help when trying to determine where the water came from and how it got into the engine. The three most common problems are “water on top of pistons, water in crankcase oil, water in crankcase oil and on top of pistons.”...

  • Page 106: Water On Top Of Pistons

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Water on Top of Pistons Cause Special Information Operator shut engine off at high rpm Poor fuel, high idle rpm, timing set too Engine “diesels” or tries to run backwards high Rain water running into flame arrestor Hatch cover Improper combustion causes moisture in Spark plug misfiring...

  • Page 107: Engine Overheats

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Engine Overheats Mechanical Cause Special Information Engine rpm below specifications at wide- Damaged or wrong propeller; growth on open-throttle (engine laboring) boat bottom; false bottom full of water Wrong ignition timing Timing too far advanced or retarded Sticking distributor advance weights Spark plug wires crossed (wrong firing order)

  • Page 108: Engine Overheats

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Engine Overheats Cooling System Cause Special Information IMPORTANT: The first step is to verify if the engine is actually overheating or the temperature gauge or sender is faulty. IMPORTANT: Best way to test gauge or sender is to replace them. Loose or broken drive belt Seawater shutoff valve partially or fully closed (if equipped)

  • Page 109: Insufficient Water Flow From Belt Driven Seawater Pickup Pump

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Insufficient Water Flow from Belt Driven Seawater Pickup Pump Cause Special Information Drive belt Loose, worn or broken Seawater shutoff valve partially or fully closed Clogged or improperly installed sea strainer Pump will suck air, pump may fail to prime Loose hose connections between seawa- or will force air bubbles into cooling ter pickup and seawater pump inlet...

  • Page 110: Power Steering

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Power Steering Poor, Erratic, or No Assist Cause Special Information Drive belt Worn, broken or out of adjustment Low fluid level Air leak in lines, pump, or air from Air in system installation. Refer to SECTION 9A for bleeding procedure.

  • Page 111: Noisy Pump

    TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Noisy Pump Cause Special Information Drive belt Check belt tension Low fluid level Air leak in lines, pump, or air from Air in fluid installation Use stethoscope to listen for noise in Faulty pump pump Kinks or debris in hoses or debris in Restricted fluid passages passages...
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  • Page 113 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 REMOVAL AND INSTALLATION Section 2A - MCM Models - Bravo and Blackhawk Drives Table of Contents Torque Specifications ....2A-2 Tools .

  • Page 114: Torque Specifications

    MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 Torque Specifications FASTENER LOCATION lb-in. lb-ft Cable Barrel Spread Cotter Key Drive Unit Drive Unit Cable End Shift Cable See Note Guide Hose Clamps Securely Rear Engine Mounts 35-40 47-54 Power Steering Fluid Hose Fitting Rear Engine Mounts...

  • Page 115: Preparation

    MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 Preparation IMPORTANT: Sterndrive unit must be removed prior to engine removal. Refer to Bravo Sterndrive Service Manual. Removal 1. Disconnect battery cables from battery. 2. Remove instrument harness connector plug from engine harness receptacle after loosening clamp.

  • Page 116: Installation

    MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 12. Support engine with suitable sling through lifting eyes on engine and remove front and rear engine mounting bolts. Retain hardware. 75505 Suitable Sling Engine Lifting Eyes 13. Carefully remove engine. DO NOT hit power steering control valve. Installation Engine Installation/Alignment 1.
  • Page 117 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 CAUTION Center lifting eye (located on top of thermostat housing) is used for engine alignment only. DO NOT use to lift entire engine. CAUTION Engine MUST be lifted with a lifting arm or damage to engine components will occur. DO NOT allow lifting sling to hook or compress engine components or damage will occur.
  • Page 118 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 10. Set engine down on stringers and relieve hoist tension. Disconnect sling from engine lifting eyes and move sling to center lifting eye. 75988 Center Lifting Eye (If Equipped) CAUTION DO NOT use an alignment tool from another manufacturer.
  • Page 119 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 c. Repeat step “b” until the alignment tool installs easily (SLIDES IN AND OUT FREELY WITH TWO FINGERS) all the way into and out of engine coupler splines. 70013 Alignment Tool (Use Only Quicksilver Alignment Tool-91-805475A1) Insert This End Of Alignment Tool Through Gimbal Housing Assembly 27647...
  • Page 120 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 h. Bend tab washer down against flat on adjusting nut. 72922 Locknut Adjustment Nut Turn Adjustment Nut In This Direction (Counterclockwise) To Raise Front Of Engine Slotted Hole To Front Of Engine Tab Washer Remove alignment tool if not already removed.
  • Page 121 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 b. On Engines with Through-Transom Exhaust: NOTICE (Through Transom Exhaust) Exhaust hoses must be connected to exhaust elbows so that they do not restrict the flow of discharge water from exhaust elbow. If hoses are connected incorrectly, discharge water from exhaust elbow will not flow around entire inside diameter of hose.

  • Page 122: Water Hose Connections

    MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 Water Hose Connections IMPORTANT: When routing all wire harnesses and hoses, be sure they are routed and secured to avoid coming in contact with hot spots on engine and avoid contact with moving parts.
  • Page 123 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 2. Connect trim position sender leads from gimbal housing to leads from engine harness. 72582 BROWN/WHITE (From Engine Harness) BLACK (From Engine Harness) BLACK (From Transom) BLACK (From Transom Assembly) IMPORTANT: Do not attach any accessory ground (–) wires to transom plate ground point.
  • Page 124 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 5. Connect wires to MerCathode controller assembly as shown. Apply a thin coat of Quick- silver Liquid Neoprene to all connections. 22232 ORANGE Wire - From Electrode On Transom Assembly RED/PURPLE Wire - Connect (Other End) To Positive (+) Battery Terminal BLACK Wire - From Engine Harness BROWN Wire - From Electrode on Transom Assembly...

  • Page 125: Fuel Supply Connections

    MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 Fuel Supply Connections WARNING Be careful when working on fuel system. Gasoline is extremely flammable and highly explosive under certain conditions. Do not smoke or allow spark or open flame in area.

  • Page 126: Throttle Cable Installation And Adjustment

    MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 Throttle Cable Installation and Adjustment MPI MODELS (EXCEPT 7.4L MPI) 1. Place remote control handle(s) in neutral idle position. IMPORTANT: Be sure that cable is routed to avoid sharp bends and/or contact with moving parts.
  • Page 127 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 3. Install cable end guide on throttle lever, then push cable barrel end lightly toward throttle lever end. (This will place a slight preload on shift cable to avoid slack in cable when moving remote control lever.) Adjust barrel on throttle cable to align with hole in anchor plate.
  • Page 128 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 7. Reinstall flame arrestor and tighten screws securely. Connect crankcase vent hose to flame arrestor as shown. 75115 Crankcase Vent Hose 7.4L MPI MODELS 1. Place remote control handle(s) in neutral idle position. 2.
  • Page 129 MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 4. Install cable end guide on throttle lever, then push cable barrel end lightly toward throttle lever end. (This will place a slight preload on shift cable to avoid slack in cable when moving remote control lever.) Adjust barrel on throttle cable to align with hole in anchor plate.

  • Page 130: Power Steering Connections

    MCM MODELS - BRAVO AND BLACKHAWK DRIVES SERVICE MANUAL NUMBER 23 7. Return remote control throttle lever to idle position and ensure that throttle plate is completely closed. 75452 Throttle Plate 8. Reinstall flame arrestor and tighten clamp securely. IMPORTANT: Adjust shift cables as outlined in appropriate Sterndrive Service Manual.
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  • Page 133 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 REMOVAL AND INSTALLATION Section 2B - MCM Models - Bravo And Blackhawk Drives With Driveshaft Extension Table of Contents Torque Specifications ....2B-2 Tools .
  • Page 134 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location lb-in. lb-ft Bearing Support (Tailstock) To Inner Transom Plate 35-40 47-54 Drive Shaft Rear Engine Mount Bracket Drive Shaft Shield Extension Housing To Flywheel Housing Flywheel Housing Power Steering Hose Fittings Remote Control Throttle Cable Cable Barrel...
  • Page 135 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 Preparation IMPORTANT: It is not necessary to remove the engine to service the drive shaft and/or bearing support (tailstock). Refer to instructions as outlined in SECTION 8F “Drive Shaft Repair”...
  • Page 136 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 Removal WARNING Be careful when working on fuel system. Gasoline is extremely flammable and highly explosive under certain conditions. Do not smoke or allow spark or open flame in area.
  • Page 137 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 Installation Engine Installation/Alignment ENGINE MOUNT ADJUSTMENT WAS NOT DISTURBED DURING SERVICE CAUTION Center lifting eye (located on top of thermostat housing) is used for engine align- ment only.
  • Page 138 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 IMPORTANT: Failure to properly position output shaft flange may result in bearing damage. 6. Relieve hoist tension from engine, then slide engine fore or aft as needed to obtain 1/4 in.
  • Page 139 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 9. Apply Loctite 271 to threads of bottom drive shaft shield retaining screws and install bottom shield on engine end as shown. Torque screws to 30 lb-ft (41 Nm). Then install top shield as shown.
  • Page 140 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 ENGINE MOUNT ADJUSTMENT WAS DISTURBED DURING SERVICE NOTE: A Universal Protractor is recommended for measuring the angles in the following steps. IMPORTANT: In the following steps, the protractor readings will be taken off of vertical and horizontal surfaces;...
  • Page 141 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 3. Adjust engine mounts so that an equal amount of up and down adjustment exists. 4. Attach a suitable lifting chain to lifting eyes on engine and adjust so that engine will be level when suspended.
  • Page 142 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 8. Relieve hoist tension from engine, then slide engine fore or aft as needed to obtain 1/4 in. (6.4 mm) between flange shoulder and extension shaft housing bearing, as shown. 72591 Flange Shoulder Bearing...
  • Page 143 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 10. After engine has been aligned correctly, fasten front and rear engine mounts to stringers. Tighten securely. 72922 Typical Mounting Shown Mounting Bolts 11. Position protractor on starter housing cover plate, as shown. Now, raise or lower front engine mount adjusting nuts as required so that protractor needle reads exactly the same number of degrees as that recorded in Step 1.
  • Page 144 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 13. Tighten ALL engine mount nuts securely. Bend washer tab down on each adjustment nut. 72922 Locknut Adjustment Nut Turn Nut In This Direction (Counterclockwise) To Raise Front Of Engine Slotted Hole Toward Front Of Engine Tab Washer 14.
  • Page 145 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 Engine Connections Water Hose Connections IMPORTANT: When routing all wire harnesses and hoses, be sure they are routed and secured to avoid coming in contact with hot spots on engine and avoid contact with moving parts.
  • Page 146 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 2. Connect trim position sender leads from gimbal housing to leads from engine harness. 72582 BROWN/WHITE (From Engine Harness) BLACK (From Engine Harness) BLACK (From Transom) BLACK (From Transom Assembly) IMPORTANT: Do not attach any accessory ground (–) wires to transom plate ground point.
  • Page 147 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 5. Connect wires to MerCathode controller assembly as shown. Apply a thin coat of Quick- silver Liquid Neoprene to all connections. 22232 ORANGE Wire - From Electrode On Transom Assembly RED/PURPLE Wire - Connect (Other End) to Positive (+) Battery Terminal BLACK Wire - From Engine Harness BROWN Wire - From Electrode on Transom Assembly...
  • Page 148 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 Fuel Supply Connections WARNING Be careful when working on fuel system. Gasoline is extremely flammable and highly explosive under certain conditions. Do not smoke or allow spark or open flame in area.
  • Page 149 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 Throttle Cable Installation and Adjustment MPI MODELS (EXCEPT 7.4L MPI) 1. Place remote control handle(s) in neutral idle position. IMPORTANT: Be sure that cable is routed to avoid sharp bends and/or contact with moving parts.
  • Page 150 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 3. Install cable end guide on throttle lever, then push cable barrel end lightly toward throttle lever end. (This will place a slight preload on shift cable to avoid slack in cable when moving remote control lever.) Adjust barrel on throttle cable to align with hole in anchor plate.
  • Page 151 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 7. Reinstall flame arrestor and tighten screws securely. Connect crankcase vent hose to flame arrestor as shown. 75115 Crankcase Vent Hose 7.4L MPI MODELS 1. Place remote control handle(s) in neutral idle position. 2.
  • Page 152 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 4. Install cable end guide on throttle lever, then push cable barrel end lightly toward throttle lever end. (This will place a slight preload on shift cable to avoid slack in cable when moving remote control lever.) Adjust barrel on throttle cable to align with hole in anchor plate.
  • Page 153 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 7. Return remote control throttle lever to idle position. Ensure that throttle plate is com- pletely closed. 75452 Throttle Plate 8. Reinstall flame arrestor and tighten clamp securely. IMPORTANT: Adjust shift cables as outlined in appropriate Sterndrive Service Manual.
  • Page 154 MCM MODELS - BRAVO AND BLACKHAWK DRIVES WITH DRIVESHAFT EXTENSION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 2B-22 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 155 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 REMOVAL AND INSTALLATION Section 2C - MIE Models - Velvet Drive Transmission Table of Contents Torque Specifications ....2C-2 Engine Connections .
  • Page 156 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Torque Specifications FASTENER LOCATION lb-ft Battery Cables Engine Mount Pads Securely Hose Clamps Securely Mount Locking Nut NOTE 2 Propeller Shaft Coupler To Transmission Output Flange Trunnion Clamping Bolt / Nut Cable Barrel Securely Remote Control Shift Cable...

  • Page 157: Preparation

    MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Preparation 1. Disconnect battery cables from battery. 2. Remove instrument panel harness connector plug from engine harness receptacle after loosening clamp. 3. Using wrench to stabilize brass coupling at fuel inlet, loosen fuel line fitting, disconnect and suitably plug fuel line to prevent fuel in tank from leaking into bilge.

  • Page 158: Installation

    MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 2. Remove front and rear engine mounting bolts. Retain hardware. 72638 All Engines Bolts Or Lag Screws (With Washers) Slot Forward (If So Designed) 3. Carefully remove engine. Installation Engine Installation and Initial Alignment 1.
  • Page 159 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 d. Each mount base is downward. Tighten clamping bolts and nuts slightly to prevent moving in or out. Mounts must be free to pivot when installing engine. 72594 72638 Front Mount - All Engine Rear Mount - Typical 71182 Rear Mount - Typical...

  • Page 160: Engine Final Alignment

    MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 IMPORTANT: Engine bed must position engine so that a minimum of 1/4 in. (6 mm) up and down adjustment still exists on all four mounts after performing final alignment. This is necessary to allow for final engine alignment. 4.
  • Page 161 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 3. Ensure coupling centerlines align by butting propeller shaft coupler against transmis- sion output flange. Shoulder on propeller shaft coupler should engage recess on trans- mission output flange face with no resistance. NOTE: Some propeller shaft couplers may not have a shoulder on mating face.
  • Page 162 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 5. If coupling centerlines are not aligned or if coupling faces are more than .003 in. (0.07 mm) out of parallel, adjust engine mounts as follows: a. TO ADJUST ENGINE UP OR DOWN: Loosen locking nut on mounts requiring adjustment and turn both front mount or rear mount adjusting nuts equally.

  • Page 163: Engine Connections

    MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 c. After engine has been properly aligned: Tighten engine mount nuts securely, and be certain to bend one of the tabs on the tab washer down onto flat of mount adjusting nut.

  • Page 164: Electrical Connections

    MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Electrical Connections 1. Connect instrument harness to engine harness with hose clamp. Tighten clamp securely. 75441 7.4L MPI Shown Instrumentation Wiring Harness Plug Fuel Supply Connections WARNING Be careful when working on fuel system. Gasoline is extremely flammable and highly explosive under certain conditions.

  • Page 165: Exhaust Hose Connection

    MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Exhaust Hose Connection 1. Connect exhaust system tubes and hoses using at least two hose clamps at each con- nection. Tighten hose clamps securely. NOTICE Exhaust hoses must be connected to exhaust elbows so that they do not restrict the flow of discharge water from exhaust elbow.
  • Page 166 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 3. On 454 Mag MPI Horizon Model: Remove flame arrestor as follows: a. Remove locknuts. 71481 Locknuts b. Move crankcase ventilation hose away from against flame arrestor and rocker arm cover fittings.
  • Page 167 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 4. Install cable end guide on throttle lever, then push cable barrel end lightly toward throttle lever end. (This will place a slight preload on shift cable to avoid slack in cable when moving remote control lever.) Adjust barrel on throttle cable to align with hole in anchor plate.
  • Page 168 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 8. On 8.2L MPI Model a. Install flame arrestor. b. Connect crankcase ventilation hose. c. Install flame arrestor screws and tighten securely. 75113 75142 8.2L MPI Shown Flame Arrestor Screws Vent Hose 9.
  • Page 169 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 7.4L MPI MODEL 1. Place remote control handle(s) in neutral idle position. 2. Remove port side engine cover. IMPORTANT: Be sure that cable is routed to avoid sharp bends and/or contact with moving parts.
  • Page 170 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 5. Secure throttle cable with hardware as shown and tighten securely. 75454 Washer and Locknut 6. Place remote control throttle lever in the wide open throttle (W.O.T.) position. Ensure that throttle plate is completely open. 75453 Throttle Plate 7.

  • Page 171: Shift Cable Installation And Adjustment

    MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Shift Cable Installation And Adjustment IMPORTANT: When installing shift cables, be sure that cables are routed in such a way as to avoid contact with moving parts and/or sharp bends [all bends must make greater than an 8 inch (203 mm) radius].
  • Page 172 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 2. Place remote control shift lever, and transmission shift lever in neutral position. 3. Remove nuts and washers from shift cable attaching studs. 4. Locate center of remote control and control shift cable play (backlash), as follows: a.
  • Page 173 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 11. Reattach nut and washer to cable barrel stud. Tighten until contact. Tighten securely, but DO NOT OVERTIGHTEN. 50947 50947 Rear Entry Single Station Rear Entry Dual Station Installation Installation In-Line And Remote V-Drive In-Line And V-Drive Cable End Guide Cable Barrel...
  • Page 174 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 NOTE: For models equipped with a dual station shift bracket such as the one shown, refer to shift cable manufacturer’s instructions for adjusting the cable. Shift lever must be positioned as stated in the preceding steps. 22457 5000 SERIES (8 DOWN ANGLE AND V-DRIVE) For Left-Hand Propeller Shaft Rotation: Shift cable hookup at remote control must result...
  • Page 175 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 IMPORTANT: The distance between studs (Dimension “C”) shown in the following illustration is set at 7-1/8 in. (318 mm). 73284 8 Down Angle Shown (V-Drive Similar) Shift Lever Anchor Stud Dimension Between Studs - 7-1/8 In.
  • Page 176 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 d. Locate center of remote control and control shift cable play (backlash) as follows: (1.) Check that remote control is in neutral position. (2.) Push in on control cable end with enough pressure to remove play; mark position “a”...
  • Page 177 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 CAUTION Remote control and shift cable must position transmission shift lever exactly as shown, or transmission failure may occur. Do not remove poppet ball or spring. 73248 Velvet Drive 5000 Series (8 Down Angle Shown, V-Drive Similar) Transmission Shift Lever Poppet Ball Must Be Centered In This Detent Hole When Left-Hand Propeller Shaft Rotation Is Desired...
  • Page 178 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 k. Install nut and washer to cable barrel stud. Tighten until contacts. Tighten securely, but DO NOT OVERTIGHTEN. 71972 71780 Typical Single Cable Installation - Rear Approach Cable End Guide Spacer (As Required) Elastic Stop Nut And Washer Bushing(s)
  • Page 179 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Index 90-861326--1 MARCH 1999 Page 2C-25 Downloaded from https://needmanual.com/...
  • Page 180 MIE MODELS - VELVET DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Index Page 2C-26 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 181 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 REMOVAL AND INSTALLATION Section 2D - MIE Models - Hurth Transmission Table of Contents Torque Specifications ....2D-2 Engine Connections .

  • Page 182: Torque Specifications

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location lb-ft Battery Cables Engine Mount Pads Securely Hose Clamps Mount Locking Nut Propeller Shaft Coupler To Transmission Output Flange Trunnion Clamping Screw / Nut Cable Barrel Securely Remote Control Shift Cable Cable End NOTE 1...

  • Page 183: Preparation

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 Preparation 1. Disconnect battery cables from battery. 2. Remove instrument panel harness connector plug from engine harness receptacle after loosening clamp. 3. Using wrench to stabilize brass coupling at fuel inlet, loosen fuel line fitting, disconnect and suitably plug fuel line to prevent fuel in tank from leaking into bilge.

  • Page 184: Installation

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 2. Remove front and rear engine mounting bolts. Retain hardware. 72638 All Engines Bolts Or Lag Screws (With Washers) Slot Forward (If So Designed) 3. Carefully remove engine. Installation Engine Installation and Initial Alignment 1.
  • Page 185 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 2. Ensure that all mounts are: a. In the center of their up and down adjustment. b. Mounting hole, which is a slot, is forward (if so designed; new style is not slotted). c.
  • Page 186 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 a. Models with Down Angle Transmission: Lift engine into boat and position on engine bed so that transmission output flange and propeller shaft coupler are visibly aligned. No gap should be seen between coupling faces when butted together. Adjust engine bed height, if necessary, to obtain proper alignment.

  • Page 187: Engine Final Alignment

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 Engine Final Alignment CAUTION To avoid vibration, noise and damage to transmission output shaft oil seal and bearings, engine must be properly aligned. IMPORTANT: Engine alignment MUST BE RECHECKED with boat in the water, fuel tanks filled and with a normal load on board.
  • Page 188 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 3. Ensure coupling centerlines align by butting propeller shaft coupler against transmis- sion output flange. Shoulder on propeller shaft coupler should engage recess on trans- mission output flange face with no resistance. NOTE: Some propeller shaft couplers may not have a shoulder on mating face.
  • Page 189 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 5. If coupling centerlines are not aligned or if coupling faces are more than .003 in. (0.07 mm) out of parallel, adjust and retighten engine mounts as follows: a. TO ADJUST ENGINE UP OR DOWN: Loosen locking nut on mounts requiring adjustment and turn both front mount or rear mount adjusting nuts equally.
  • Page 190 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 c. After engine has been properly aligned: Tighten engine mount nuts securely, and be certain to bend one of the tabs on the tab washer down onto flat of mount adjust- ing nut.

  • Page 191: Engine Connections

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 Engine Connections Seawater Hose Connection IMPORTANT: When routing all wire harnesses and hoses, be sure they are routed and secured to avoid coming in contact with hot spots on engine and avoid contact with moving parts.

  • Page 192: Fuel Supply Connections

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 Fuel Supply Connections WARNING Be careful when working on fuel system. Gasoline is extremely flammable and highly explosive under certain conditions. Do not smoke or allow spark or open flame in area. Wipe up any spilled fuel immediately. WARNING Avoid gasoline fire or explosion.

  • Page 193: Exhaust Hose Connection

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 Exhaust Hose Connection 1. Connect exhaust system tubes and hoses using at least two hose clamps at each connection. Tighten hose clamps securely. NOTICE Exhaust hoses must be connected to exhaust elbows so that they do not restrict the flow of discharge water from exhaust elbow.
  • Page 194 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 3. On 454 Mag MPI Horizon Model: Remove flame arrestor as follows: a. Remove locknuts. 71481 Locknuts b. Move crankcase ventilation hose away from flame arrestor and rocker arm cover fit- tings.
  • Page 195 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 4. Install cable end guide on throttle lever, then push cable barrel end lightly toward throttle lever end. (This will place a slight preload on shift cable to avoid slack in cable when moving remote control lever.) Adjust barrel on throttle cable to align with hole in anchor plate.
  • Page 196 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 8. On 8.2L MPI Model: Install flame arrestor as follows: a. Install flame arrestor. b. Connect crankcase ventilation hose. c. Install flame arrestor screws and tighten securely. 75113 75142 8.2L MPI Shown Flame Arrestor Screws Crankcase Ventilation Hose...
  • Page 197 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 c. Position crankcase ventilation hose against flame arrestor and rocker arm cover fittings as shown. 71764 Crankcase Vent Hose 7.4L MPI MODEL 1. Place remote control handle(s) in neutral idle position. 2.
  • Page 198 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 5. Secure throttle cable with hardware as shown and tighten securely. 75454 Washer and Locknut 6. Place remote control throttle lever in the wide open throttle (W.O.T.) position. Ensure that throttle plate is completely open. 75453 Throttle Plate 7.

  • Page 199: Shift Cable Installation And Adjustment

    MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 Shift Cable Installation And Adjustment IMPORTANT: These Hurth transmissions are full reversing transmissions. Direction of output/propeller rotation is determined by hookup of shift cable at remote control. Shift cable must be hooked up to remote control before starting installation and adjustment procedures.
  • Page 200 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 2. Check shift lever positioning as indicated. IMPORTANT: Ensure that shift lever is positioned approximately 10 aft of vertical when in the neutral detent position and that the distance (“c”) between studs in the following is set at 7-1/8 in.
  • Page 201 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 6. Center cable end play. Adjust cable barrel to align holes in barrel and in cable end guide with attaching points on transmission. 7. Temporarily install shift cable. Do not secure at this time. 73587 Typical Shift Cable End Guide...
  • Page 202 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 12. Reattach locknut and washer to cable barrel stud. Tighten until contacts. Tighten securely, but DO NOT OVERTIGHTEN. NOTE: To change cable approach direction on single or dual station installations, only the spacers/bushings have to be switched to the opposite stud (the studs are identical).
  • Page 203 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 71211 73590 Typical Dual Cable - Forward Entry Cable End Guides Locknut And Washer Spacer (Fits Over Stud) Bushings Cable Barrel Locations Cable Barrel Stud Cable End Guide Stud 50073 73591 Typical Dual Cable - Rear Entry Cable End Guides Locknut And Washer...
  • Page 204 MIE MODELS - HURTH TRANSMISSION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 2D-24 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 205 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 ENGINE Section 3A - 454 cid (7.4L) / 502 cid (8.2L) Table of Contents Torque Specifications ....3A-3 Cylinder Head and Valve Conditioning 3A-41...
  • Page 206 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Crankshaft ......3A-74 Camshaft Bearings .
  • Page 207 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Torque Specifications DESCRIPTION lb-in. lb-ft Alternator Bracket to Engine Alternator to Mounting Bracket (Pivot) Alternator to Mounting Bracket (Anchor) Camshaft Sprocket Gear 7.4L MPI (3/8-24 Nuts) 454 / 502 Connecting Rod Caps Mag MPI (7/16-20...
  • Page 208 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Torque Specifications (Continued) DESCRIPTION lb-in. lb-ft 7.4L MPI 454 / 502 Plenum to Intake Mag MPI and 8.2L 7.4L MPI 454 / 502 Main Bearing Caps Mag MPI and 8.2L Oil Baffle Nuts Oil Filter Adapter Nuts Oil Pan Bolts...
  • Page 209 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Tools MERCURY MARINE SPECIAL TOOLS DESCRIPTION PART NUMBER Piston Ring Expander 91-24697 Engine Coupler Wrench 91-35547 Special Tools KENT-MOORE SPECIAL TOOLS Kent-Moore Special Tools 29784 Little Mack Roseville, MI 48066...
  • Page 210 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Lubricants / Sealants / Adhesives DESCRIPTION PART NUMBER Quicksilver Loctite 27131 92-809820 Quicksilver Perfect Seal 92-34227--1 Quicksilver RTV Sealer / Loctite 587 92-809826 General Motors Cam and Lifter Prelube or Obtain Locally Equivalent Engine Specifications...

  • Page 211: Mag / 502 Mag / 8.2L

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 454 Mag / 502 Mag / 8.2L (Except 7.4L MPI L-29) Engine Specifications (Continued) CYLINDER BORE MODEL 454 MAG 502 MAG / 8.2L 4.2451-4.2525 4.4655-4.4662 Diameter (107.826-108.013) (113.423-113.441) Production .001 (0.025) Max Out of Round Out of Round...
  • Page 212 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 454 Mag / 502 Mag / 8.2L (Except 7.4L MPI L-29) Engine Specifications (Continued) PISTON RING MODEL 454 MAG 502 MAG / 8.2L .0017-.0032 .0017-.0032 (0.044-0.081) (0.044-0.081) Production Production Groove Side .0017-.0032 .0017-.0032...
  • Page 213 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 454 Mag / 502 Mag / 8.2L (Except 7.4L MPI L-29) Engine Specifications (Continued) CRANKSHAFT MODEL 454 MAG 502 MAG / 8.2L No.1,2,3,4, Diameter 2.7482-2.7489 (69.8042-69.8220) Production .0002 (0.005) Max Main Main Taper...
  • Page 214 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 454 Mag / 502 Mag / 8.2L (Except 7.4L MPI L-29) Engine Specifications (Continued) VALVE SYSTEM MODEL 454 MAG 502 MAG / 8.2L Lifter Hydraulic Rocker Arm Ratio 1.70 to 1 Face Angle (Intake &...
  • Page 215 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 454 Mag / 502 Mag / 8.2L (Except 7.4L MPI L-29) Engine Specifications (Continued) ROLLER TAPPET CAMSHAFT MODEL 454 MAG / 502 MAG / 8.2L Exhaust .301 (7.645) Lobe Lift Lobe Lift .020 (0.051) 020 (0 051)
  • Page 216 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 7.4L MPI (L-29) Engine Specifications NOTICE Unit Of Measurement: U.S. Quarts (Liters) All capacities are approximate fluid measures. MODEL 7.4L Displacement 454 cid (7.4L) Bore 4.25 (108) Stroke 4.00 (101.6) Compression Ratio 9.3:1 Heads...
  • Page 217 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 7.4L MPI (L-29) Engine Specifications (Continued) PISTON RING MODEL 7.4L Production .0012-.0029 (0.0304-0.0737) Groove Side Groove Side High Production Limit + .010 Clearance Service (0.254) Max Compression .010-.018 (0.254-0.457) Production Production .016-.024 (0.406-0.6096)
  • Page 218 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 7.4L MPI (L-29) Engine Specifications (Continued) CRANKSHAFT MODEL 7.4L No. 1, 2, 3, 4, 2.7482-2.7489 Diameter (69.8040-69.8220) Production .0004 (0.0101) Max Taper Ta er Main Journal Main Journal Service .001 (0.0254) Max Production .0004 (0.0101) Max...
  • Page 219 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 7.4L MPI (L-29) Engine Specifications (Continued) VALVE SYSTEM MODEL 7.4L Lifter Hydraulic Roller Rocker Arm Ratio 1.70 to 1 Face Angle (Intake & Exhaust) Seat Angle (Intake & Exhaust) Seat Runout (Intake &...

  • Page 220: General Information

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 General Information Some of the repairs in this section must be completed with engine removed from boat. Engine removal depends upon type of repair and boat design. Place engine on repair stand for major repairs.

  • Page 221: Cylinder Head Identification

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Cylinder Head Identification 7.4L MPI Cylinder heads are identified by their smaller and rounded intake ports. 72913 454 MAG MPI / 502 MAG MPI / 8.2L MPI Cylinder heads are identified by their large rectangular intake ports. 72914 Engine Rotation Engine rotation terminology at times has caused confusion.

  • Page 222: Crankshaft

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Crankshaft The crankshaft is supported in the block by five insert type bearings. Crankshaft end thrust is controlled by flanges on the No. 5 bearing. A torsional damper on the forward end of the crankshaft serves to help dampen any engine torsional vibration.
  • Page 223 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 After leaving the pump, the pressurized oil flows through a full-flow oil filter. On engines with an engine oil cooler, the oil also flows through the cooler before returning to the block. A bypass valve allows oil to bypass the filter and oil cooler should they become restricted.

  • Page 224: Bearing Failures

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Bearing Failures 70436 Scratched By Dirt Scratches Dirt Imbedded In Bearing Material 70436 Tapered Journal Overlay Gone From Entire Surface 70436 Lack Of Oil Overlay Worn Off 70436 Radius Ride Worn Area Index Page 3A-20...
  • Page 225 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 70436 Improper Seating Bright Or Polished Sections 70436 Fatigue Failure Craters or Pockets Index 90-861326--1 MARCH 1999 Page 3A-21 Downloaded from https://needmanual.com/...

  • Page 226: Piston Failures

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Piston Failures Pre-Ignition Pre-ignition is abnormal fuel ignition, caused by combustion chamber hot spots. Control of the start of ignition is lost, as combustion pressure rises too early, causing power loss and rough running.

  • Page 227: Detonation

    NOTE: Engine failures, which result from the foregoing conditions, are beyond the control of Mercury Marine; therefore, no warranty will apply to failures which occur under these con- ditions. Detonation Detonation, commonly called “fuel knock,”...
  • Page 228 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 NOTE: Engine failures, which result from the foregoing conditions, are beyond the control of MerCruiser; therefore, no warranty will apply to failures which occur under these condi- tions. 72425 Detonation Damage 72315 Combustion Description...

  • Page 229: Engine Mounts

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Engine Mounts 72317 Front Mount - All MCM (Sterndrive) Models 72318 Rear Mount/Flywheel Housing - All MCM (Sterndrive) Models Index 90-861326--1 MARCH 1999 Page 3A-25 Downloaded from https://needmanual.com/...
  • Page 230 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Engine Mounts (Continued) 73055 Rear Mount Assembly - Most MIE Models 73056 Rear Mount Assembly - MIE Models with Velvet Drive In-Line Transmission Index Page 3A-26 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 231 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Engine Mounts (Continued) 72319 Front Mount Assembly - All MIE Models 72319 Rear Mount Assembly - MIE 7.4L with Velvet Drive Remote V-Drive Transmission Index 90-861326--1 MARCH 1999 Page 3A-27 Downloaded from https://needmanual.com/...

  • Page 232: Rocker Arm Cover

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Rocker Arm Cover Removal It may be necessary to remove exhaust manifold before removing rocker arm cover. Refer to SECTION 7B for removal. Also remove any component that will interfere with the removal of the manifold.

  • Page 233: Intake Manifold

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Intake Manifold NOTICE For repair procedures on “Fuel Injection Engines,” refer to Section 5C. Removal 1. Drain engine cooling system. 2. Disconnect hoses from thermostat housing. 3. Disconnect intake manifold-to-circulating pump by-pass hose from circulating pump. 4.

  • Page 234: Installation

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Installation IMPORTANT: When installing intake manifold gaskets, in next step, be sure to do the following: Be sure to install gasket with marked side up. Both gaskets are identical. 1.
  • Page 235 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 5. Follow step “a” for 454 Mag / 502 Mag / 8.2L and step “b” for 7.4L MPI engines. a. Carefully install manifold assembly. Torque in sequence to 35 lb-ft (48 Nm). 75640 Intake Manifold Torque Sequence For 454 Mag / 502 Mag / 8.2L MPI Engines b.

  • Page 236: Rocker Arm/Push Rod

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Rocker Arm/Push Rod Removal NOTE: When servicing only one cylinder’s rocker arms, bring that cylinder’s piston up to TDC before removing rocker arms. When servicing all rocker arms, bring No. 1 piston up to TDC before removing rocker arms.

  • Page 237: Rocker Arm Stud Kit

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Rocker Arm Stud Kit These engines use a net lash or non-adjustable rocker arm system. Torquing the rocker arm bolt to 40 lb-ft (54 Nm) sets the valve lash. When rebuilding these engines with a net lash, machining of the cylinder deck surface or cylinder head surface or grinding the valve seats or valves may cause an incorrect valve lash condition.

  • Page 238: Locating Noisy Lifters

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Locating Noisy Lifters Locate a noisy valve lifter by using a piece of garden hose approximately 4 ft (1.2 m) in length. Place one end of hose near end of each intake and exhaust valve, with other end of hose to the ear.

  • Page 239: Removal

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Removal IMPORTANT: Keep push rod and hydraulic valve lifter from each valve together as a matched set and mark them so they can be reinstalled in the same location later. Remove as outlined: 1.

  • Page 240: Valve Stem Oil Seal / Valve Spring

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Valve Stem Oil Seal / Valve Spring Removal - Head Installed 1. Remove: a. Rocker arm cover. b. Spark plug of affected cylinder. c. Rocker arm assembly. 2. Install air line adaptor tool (J-23590) in spark plug hole and apply compressed air to hold valves in place.

  • Page 241: Valve Assembly (Exploded View)

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Valve Assembly (Exploded View) 75721 7.4L Valve Lock Retainer Oil Shield Seal Oil Shield Outer Spring Rotator Intake Valve Exhaust Valve 72278 454 Mag / 502 Mag / 8.2L Valve Lock Retainer Oil Shield...

  • Page 242: Valve Installation - Head Installed

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Valve Installation - Head Installed 7.4L 1. Place rotator or shim on valve spring seat. 2. Coat valve stem and new seal with engine oil. Install seal over valve stem. 3.

  • Page 243: Cylinder Head

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 3. Place valve spring assembly in position with tighter wound coils against spring seat. IMPORTANT: Valve seal and cap must be assembled as shown before installation. 72149 4. Coat valve stem and new seal with engine oil. 5.
  • Page 244 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Installation CAUTION DO NOT use sealer on head gaskets. 1. Place head gasket in position over dowel pins. 2. Carefully set cylinder head in place over dowel pins. 3. Coat threads of head bolts with Quicksilver Perfect Seal and install finger-tight. 4.

  • Page 245: Cylinder Head And Valve Conditioning

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Cylinder Head and Valve Conditioning Disassembly 1. Using valve spring compressor, compress valve spring and remove valve locks. Slowly release tool. 72565 Valve Spring Compressor (J-8062) 2. Remove all valve components. 3.

  • Page 246: Inspection

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 5. Thoroughly clean valve guides with valve guide cleaner. 72564 Valve Guide Cleaner (J-8101) Inspection 1. Inspect cylinder heads for cracks in exhaust ports, water jackets and combustion cham- bers (especially around spark plug holes and valve seats).

  • Page 247: Valve Guide Bore Repair

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 IMPORTANT: Excessive valve stem to bore clearance will cause excessive oil con- sumption and possible valve breakage. Insufficient clearance will result in noisy and sticky valves. 5. Measure valve stem clearance as follows: a.

  • Page 248: Valve Springs - Checking Tension

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Valve Springs - Checking Tension IMPORTANT: Springs should be replaced if not within 10 lb. (44 N) of specified tension. 72308 Valve Spring Tester (J-8056) Torque Wrench Valve Seat Repair Valve seat reconditioning is very important, since seating of valves must be perfect for engine to deliver maximum power and performance.

  • Page 249: Valve Grinding

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Regardless of type of equipment, however, it is essential that valve guide bores be free from carbon or dirt to achieve proper centering of pilot in valve guide, ensuring concentricity. 72568 Measuring Valve Seat Concentricity Valve Grinding...

  • Page 250: Reassembly

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Reassembly 1. Lubricate valve guides and valve stems with engine oil. 2. Install each valve in the port from which it was removed or to which it was fitted. 3.
  • Page 251 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 5. Slowly release tool, making sure valve locks seat properly in grooves of valve stem. 75721 7.4L Valve Lock Retainer Oil Shield Seal Oil Shield Outer Spring Rotator Intake Valve Exhaust Valve 72278 454 Mag / 502 Mag / 8.2L...

  • Page 252: Crankcase Oil Dipstick Specifications

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 6. Check installed height of valve springs using a narrow, thin scale cutaway as shown. Measure from spring seat to top of valve spring, as shown. If measurement exceeds specified height, install a valve spring shim and recheck.

  • Page 253: Oil Pan

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Oil Pan Removal 1. Drain crankcase oil. 2. Remove dipstick and tube, or tubes, if equipped with two. Note shape of port and star- board tubes as shown following to aid in reassembly. IMPORTANT: DO NOT move or disturb the orientation of fitting on bottom of pan or incorrect oil level readings may be obtained.
  • Page 254 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 3. Install oil pan gasket in position as shown. NOTE: A one-piece oil pan gasket may be re-used if it is still pliable and is not cracked, torn or otherwise damaged. 75496 Oil Pan Gasket 4.

  • Page 255: Oil Pump

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Oil Pump 72277 Oil Pump Assembly Extension Shaft Shaft Coupling Pump Body Drive Gear and Shaft Idler Gear Pickup Screen and Pipe Pump Cover Pressure Regulator Valve Pressure Regulator Spring 10 - Retaining Pin 11 -...

  • Page 256: Disassembly

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Disassembly NOTE: Refer to exploded view shown previously. 1. Remove pump cover. IMPORTANT: Mark gear teeth for reassembly with same teeth indexing. 2. Remove idler gear and drive gear from pump body. 3.

  • Page 257: Installation

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Installation 1. Install pump, with extension shaft, to rear main bearing, aligning extension shaft with distributor drive shaft. 2. Install baffle. Tighten baffle nuts to 25 lb-ft (34 Nm). Tighten oil pump bolt to 65 lb-ft (90 Nm).

  • Page 258: Installation

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Installation IMPORTANT: The inertia weight section of torsional damper is assembled to the hub with a rubber type material. The installation procedure (with proper tool) must be fol- lowed or movement of the inertia weight on the hub will destroy the tuning of the tor- sional damper.

  • Page 259: Front Cover / Oil Seal

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Front Cover / Oil Seal Oil Seal Replacement (Without Removing Front Cover) REMOVAL 1. Remove torsional damper. 2. Pry seal out of cover from the front with a large screwdriver, being careful not to distort front cover or damage crankshaft.

  • Page 260: Front Cover

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Front Cover Removal 1. Remove engine from boat. 2. Remove torsional damper. 3. Remove oil pan. 4. Remove water circulating pump. 5. Remove front cover. 6. If damaged, drive oil seal out of front cover (from the rear) using a punch. Cleaning 1.
  • Page 261 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 8. Fill crankcase with engine oil. 9. Follow procedures in SECTION 6A or 6B of this manual: Seawater Cooled Models: Provide adequate water supply to seawater pickup (see SECTION 6A). Closed Cooled Models: Refill closed cooling section (see SECTION 6B), and provide adequate water supply to seawater pickup.

  • Page 262: Flywheel

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Flywheel Removal 1. Remove engine from boat. 2. Remove transmission, if equipped. 3. Refer to “Flywheel Housing” description in this section and remove flywheel housing and related parts. 4. Remove MCM coupler or MIE drive plate. 5.

  • Page 263: Inspection

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Inspection 1. Inspect splines in drive plate or coupler for wear. 2. Check flywheel ring gear for worn and missing teeth. Installation NOTE: If crankshaft is to be replaced, but old pilot bushing is to be reused, bushing can be removed without damage by filling pilot bushing cavity with grease, then inserting an old transmission input shaft in bore of bushing and hitting it with a hammer.

  • Page 264: Rear Main Oil Seal

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Rear Main Oil Seal The rear crankshaft oil seal can be replaced without removing the oil pan or rear main bear- ing cap from engine. Removal Remove seal by using a screwdriver to pry it out of engine block as shown. 72559 Rear Main Seal (Crankshaft Oil Seal) IMPORTANT: Do not nick or gouge the engine block or rear main bearing cap sealing...

  • Page 265: Installation

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Installation 1. Apply Quicksilver Perfect Seal to engine block/seal mating surface. Apply grease to seal lips. 2. Install seal using rear main seal installer or suitable device. 72356 Suitable Device Shown (Rear Main Seal Installer J-38841 Not Shown) Main Bearings IMPORTANT: Before removing main bearing caps or connecting rod caps, mark them for reassembly in their original locations.
  • Page 266 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 2. Place a piece of gauging plastic the full width of the bearing (parallel to the crankshaft) on the journal as shown. IMPORTANT: Do not rotate the crankshaft while the gauging plastic is between the bearing and journal.

  • Page 267: Replacement

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 journal is out of round .001 in., interference between the bearing and journal will result in rapid bearing failure. If the flattened gauging plastic tapers toward the middle or ends, there is a difference in clearance indicating taper, low spot or other irregularity of the bearing or journal.
  • Page 268 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 WITH CRANKSHAFT REMOVED 1. Remove and inspect the crankshaft as outlined. 2. Remove the main bearings from the cylinder block and main bearing caps. 3. Coat bearing surfaces of new, correct size, main bearings with oil and install in the cylin- der block and main bearing caps.

  • Page 269: Connecting Rod Bearings

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Connecting Rod Bearings Connecting rod bearings are of the precision insert type and do not use shims for adjust- ment. DO NOT FILE RODS OR ROD CAPS. If clearances are found to be excessive, a new bearing will be required.
  • Page 270 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 IMPORTANT: Do not turn the crankshaft with the gauging plastic installed. 72362 6. If the clearance exceeds specifications, select a new, correct size bearing and measure the clearance. Be sure to check what size bearing is being removed in order to determine proper replace- ment size bearing.

  • Page 271: Connecting Rod / Piston Assembly

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Connecting Rod / Piston Assembly Removal 1. Remove as outlined: a. Oil pan and dipstick tube. b. Baffle and oil pump. c. Distributor and intake manifold. d. Cylinder heads. 2.
  • Page 272 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Disassembly Disassemble piston from connecting rod using piston pin remover as shown. Follow instruc- tions supplied with kit. 72365 Piston Pin Remover and Installer Kit (J-24086-C) Arched Base Piston Connecting Rod Rod Support Cleaning and Inspection...
  • Page 273 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 5. Slip outer surface of a new top and second compression ring into respective piston ring groove and roll ring entirely around the groove to make sure that ring is free as shown. If binding occurs at any point, determine cause.
  • Page 274 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Reassembly IMPORTANT: Reassembly of pistons and connecting rods require adherence to the following steps. Piston and pin are machine fitted to each other and must remain together as a matched set.
  • Page 275 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 1. Assemble piston to connecting rod using piston pin remover as shown. Follow instruc- tions supplied with kit. 72371 Piston Pin Remover (J-24086-C) 2. Once assembled, check piston for freedom of movement (back-and-forth and up-and-down) on connecting rod.
  • Page 276 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 6. Clean and inspect pistons, if not previously done. 7. Install piston rings as follows: a. Install oil ring spacer in groove and insert anti-rotation tang in oil hole. b.
  • Page 277 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 4. Install each connecting rod and piston assembly in its respective bore. Install with con- necting rod bearing tangs toward outside of cylinder block. Use piston ring compressor to compress rings. Guide connecting rod into place on crankshaft journal with connect- ing rod bolt guide.

  • Page 278: Crankshaft

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Crankshaft Removal 1. Remove engine from boat. 2. Drain crankcase oil. 3. Remove as outlined: a. Starter. b. Flywheel housing. c. Drive coupler/plate and flywheel. d. Belts. e. Water pump. Crankshaft pulley and torsional damper.
  • Page 279 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Installation 1. If a new crankshaft is being installed, proceed as follows: a. Remove timing sprocket or gear from old crankshaft and reinstall on new crankshaft as outlined. b. On models with drive shaft extension, if old pilot bushing is to be reused, bushing can be removed without damage by filling pilot bushing cavity with grease, then inserting an old transmission input shaft in bore of bushing and hitting it with a hammer.

  • Page 280: Timing Chain And Sprocket

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Timing Chain and Sprocket Removal 1. Remove torsional damper, oil pan and front cover as outlined. 2. Turn crankshaft until timing marks on crankshaft and camshaft sprockets are in align- ment as shown.

  • Page 281: Crankshaft Sprocket

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Crankshaft Sprocket Removal 1. Remove torsional damper and crankcase front cover as outlined. 2. Remove camshaft timing chain as outlined. 3. Remove crankshaft sprocket using crankshaft gear and sprocket puller (J-24420-B). Installation 1.

  • Page 282: Camshaft

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Camshaft Measuring Lobe Lift NOTE: Procedure is similar to checking valve timing. If improper valve operation is indi- cated, measure lift of each push rod in consecutive order and record readings. 1.

  • Page 283: Inspection

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Inspection Measure camshaft bearing journals with a micrometer for out-of-round condition. If journals exceed .001 in. (0.025 mm) out-of-round, camshaft should be replaced. Also check camshaft for alignment with V-blocks and dial indicator which indicates exact amount camshaft is out of true.

  • Page 284: Inspection

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 5. Remove remaining bearings (except front and rear) in same manner. It will be necessary to position pilot in rear camshaft bearing to remove rear intermediate bearing. 72571 Index Point Puller Screw Driver Bearing...

  • Page 285: Cylinder Block

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 1. Installing intermediate and center bearings: a. Install nut and thrust washer all the way onto puller screw, then position pilot in front camshaft bearing bore and insert screw through pilot. b.
  • Page 286 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 3. Measure cylinder walls for taper, out-of-round or excessive ridge at top of ring travel. This should be done with a dial indicator or inside micrometer. Carefully work gauge up and down cylinder to determine taper and turn it to different points around cylinder wall to determine out-of-round condition.
  • Page 287 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 4. Check cylinder head gasket surfaces for warpage with a machinist’s straight-edge and a feeler gauge, as shown. Take measurements diagonally across surfaces (both ways) and straight down center. If surfaces are warped more than .003 in. (0.07 mm) in a 6 in. area or .007 in.
  • Page 288 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 3. When finish-honing a cylinder bore to fit a piston, move hone up and down at a sufficient speed to obtain very fine uniform surface finish marks in a crosshatch pattern of approxi- mately 30 degrees to cylinder bore.

  • Page 289: Compression Test 3A-85

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 2. If used piston is not satisfactory, determine if a new piston can be selected to fit cylinder bore within acceptable range. 3. If cylinder bore must be reconditioned, measure new piston diameter (across centerline of piston pin), then hone cylinder bore to correct clearance (preferable range).

  • Page 290: Oil Filter By-Pass Valve And Adaptor 3A-86

    454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 Oil Filter By-Pass Valve and Adaptor CAUTION Engine with front mounted vertical oil cooler MUST have a 30 psi oil pressure relief valve installed. Severe engine damage or failure will occur if not installed. Inspection and / or Replacement Oil by-pass valve and adaptor should be inspected whenever engine is disassembled for major repair or whenever inadequate oil filtration is suspected.
  • Page 291 454 CID (7.4L) / 502 CID (8.2L) SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 3A-87 Downloaded from https://needmanual.com/...
  • Page 292 STARTING SYSTEM SERVICE MANUAL NUMBER 23 ELECTRICAL SYSTEMS Section 4A - Starting System Table of Contents Starting System Components ..4A-2 PG 260 Starter Motor Repair ..4A-20 Direct Drive Starter Motor .

  • Page 293: Starting System Components

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Starting System Components (Typical for All Starters) 72930 Ignition Switch 20 Amp Fuse Starter Slave Solenoid Circuit Breaker Starter Motor Wire Junction Neutral Safety Switch 90 Amp. Fuse Engine Ground (–) Index Page 4A-2 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...

  • Page 294: Direct Drive Starter Motor

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Direct Drive Starter Motor Identification The starter identification number is located as shown. 72789 Identification Number Electrical Circuit Description This is a general description of the positive current flow, from the battery and through the system until the starter motor cranks.

  • Page 295: Specifications

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Specifications Starter Specifications Direct Drive Starter Motor Engine Brush No Load Test Delco Iden- Rotation Spring tification tification Tension Oz. Min. Max. Min. Max. Number Volts (Grams) Amps Amps 56-105 10455602 10.6 5400 10800 (1588-2976) Pinion Clearance .010-.140 (0.25-3.5 mm)
  • Page 296 STARTING SYSTEM SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 4A-5 Downloaded from https://needmanual.com/...

  • Page 297: Direct Drive Starter Motor Exploded View 4A-6

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Direct Drive Starter Motor Exploded View 72806 Index Page 4A-6 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...

  • Page 298: Preparation

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 End Housing End Housing Bushing Thrust Collar Retaining Ring - Pinion Stop Collar Pinion Stop Collar Clutch Drive Assembly Bearing Plate Bearing Plate Bushing Bearing Plate Washer 10 - Bearing Plate Screw 11 - Armature 12 - Pole Shoe - Field Coil...

  • Page 299: Starter Motor Disassembly

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Starter Motor Disassembly 1. Remove screw from field coil connector. 72631 Connector Screw 2. Remove end frame screw/studs, end frame, washer and field frame. 72633 Screw/Studs End Frame Washer Field Frame 3. Remove screws, center bearing plate and armature. 72634 Screws Bearing Plate...

  • Page 300: Cleaning

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Cleaning IMPORTANT: DO NOT use grease dissolving solvents for cleaning over-running clutch, armature and field coils. Such a solvent would dissolve grease packed in clutch mechanism and damage armature and field coil insulation. Inspection With starting motor completely disassembled, except for removal of field coils, component parts should be cleaned and inspected.
  • Page 301 STARTING SYSTEM SERVICE MANUAL NUMBER 23 d. Drive snap ring onto shaft and slide down into groove. 72073 Snap Ring Groove e. Assemble thrust collar on shaft with shoulder next to snap ring. Place thrust collar and retainer next to snap ring and using two pliers squeeze both until snap ring is forced into retainer.

  • Page 302: Pinion Clearance

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Pinion Clearance Pinion clearance must be checked as follows after reassembly of motor to insure proper adjustment. 1. Disconnect motor field coil connector from solenoid motor terminal and insulate it care- fully. 72631 Motor Field Coil Connector 2.

  • Page 303: Commutator End Frame Gap

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 6. If clearance is not within limits of .010-.140 in. (0.25-3.5 mm), it may indicate excessive wear of solenoid linkage shift lever yoke buttons or improper assembly of shift lever mechanism. Check for proper assembly, and recheck gap. If still excessive, replace worn or defective parts, since no provision is made for adjusting pinion clearance.

  • Page 304: Testing

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Testing ARMATURE TESTS Test for Shorts 1. Check armature for shorts by placing on growler and holding hack saw blade over armature core while rotating armature. If saw blade vibrates, armature is shorted. After cleaning between commutator bars, recheck.

  • Page 305: Field Coil Tests

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Field Coil Tests TEST FOR OPEN CIRCUIT 1. With continuity meter, place one lead on each end of field coils (insulated brush and field connector bar). 72635 2. If meter does not move, field coils are open and must be replaced. Index Page 4A-14 90-861326--1 MARCH 1999...

  • Page 306: Loose Electrical Connections

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 TEST FOR GROUND IMPORTANT: Be sure that positive brushes and leads do not contact field frame assembly during test, or false reading will result. 1. With continuity meter, place one lead on field connector bar and other lead on grounded brush.

  • Page 307: Delco Pg260 Starter Motor

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Delco PG260 Starter Motor Identification 74041 Electrical Circuit Description This is a general description of the positive current flow, from the battery and through the system until the starter motor cranks. Battery to the solenoid switch (on starter) (RED battery cable). Solenoid switch to circuit breaker (RED).

  • Page 308: Specifications

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Specifications PG260 Specifications Delco I.D. Number MerCruiser Part Number 9000820 50-806963 No Load Test Brush Spring Engine Engine Tension Oz. Min. Rotation Volts Max. Amp Min. rpm Max. rpm (Grams) Amps 83-104 oz. 10.6 2750 3250 (2352- 2948)

  • Page 309: Torque Specifications

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location lb-ft Starter Motor To Block All Other Fasteners Tighten Securely Lubricants / Sealants / Adhesives Description Part Number Quicksilver Liquid Neoprene 92-25711--3 SAE 10W Oil Obtain Locally Obtain Locally SAE 20W Oil Index Page 4A-18 90-861326--1 MARCH 1999...

  • Page 310: Pg 260 Starter Motor Exploded View

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 PG 260 Starter Motor Exploded View 74270 Screw (2) End Cap Brush With Holder Armature Field Frame (With Permanent Magnets) Washer Shield Planetary Gears Shaft 10 - Gear 11 - Drive 12 - Collar 13 - Retaining Ring 14 -...

  • Page 311: Preparation

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Preparation WARNING Disconnect battery cables at battery before removing starter. 1. Disconnect battery cables from battery. 2. Disconnect wires from solenoid terminals. Removal IMPORTANT: Some starter motors may use a special mounting shim for gaining fly- wheel clearance.

  • Page 312: Disassembly

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Disassembly 1. Remove brush lead from solenoid and screws from end frame. 74041 Brush Lead Screws 2. Remove screws and separate end frame from field frame and end cap. 74040 End Cap Screws Drive Housing 3.
  • Page 313 STARTING SYSTEM SERVICE MANUAL NUMBER 23 4. Remove armature and field frame from drive housing. 5. Pull armature out of field frame. NOTE: Permanent magnets inside field frame will be holding armature in place. 74086 Armature Field Frame 6. Remove shield and washer. 74038 Shield Washer...
  • Page 314 STARTING SYSTEM SERVICE MANUAL NUMBER 23 8. Remove drive and associated parts from drive housing. 74035 Drive Housing Drive 9. Remove solenoid arm and rubber grommet from the drive housing. 74105 74048 74018 Rubber Grommet Solenoid Arm Drive Housing Index 90-861326--1 MARCH 1999 Page 4A-23 Downloaded from...

  • Page 315: Cleaning And Inspection

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 10. Remove thrust collar, retaining ring and collar from planetary gear shaft assembly. 74016 Thrust Collar Retaining Ring Collar Drive 11. Remove drive and gear from planetary shaft. 74087 Gear Planetary Gear Shaft Assembly Drive Cleaning and Inspection IMPORTANT: Do not use grease dissolving solvents to clean electrical components,...

  • Page 316: Armature Tests

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Armature Tests TEST FOR SHORTS 1. Check armature for shorts by placing on growler and holding hack saw blade over armature core while rotating armature. If saw blade vibrates, armature is shorted. After cleaning between commutator bars, recheck. If saw blade still vibrates, replace armature.

  • Page 317: Brushes And Brush Holder

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Brushes and Brush Holder INSPECTION Replace brushes and holder when brush leads are touching guide. Make sure brushes move freely in guides. 72069 Brush Leads Guide INSTALLATION 1. Push each brush up into its guide, use a 3 inch (75 mm) piece of coat hanger wire or similar stiff wire to retain the spring while installing armature, as shown.

  • Page 318: Reassembly

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 2. Place brush holder on armature and remove pieces of wires from brush holder. 72069 Brush Holder Brush Reassembly 1. Install end frame on brush holder. Align holes of end frame with holes of brush holder. Tighten screws securely.
  • Page 319 STARTING SYSTEM SERVICE MANUAL NUMBER 23 3. Assemble drive on shaft assembly as follows: a. Lubricate drive end of shaft assembly with SAE 10W oil. b. Place gear over shaft. c. Slide drive assembly onto shaft with pinion facing outward. d.
  • Page 320 STARTING SYSTEM SERVICE MANUAL NUMBER 23 4. Install solenoid arm and rubber grommet in the drive housing. 74105 74048 74018 Rubber Grommet Solenoid Drive Housing 5. Install drive and associated parts in drive housing. 74035 Drive Housing Drive Index 90-861326--1 MARCH 1999 Page 4A-29 Downloaded from https://needmanual.com/...
  • Page 321 STARTING SYSTEM SERVICE MANUAL NUMBER 23 6. Place solenoid in drive housing and tighten screws. 74036 Drive Housing Solenoid Screw (3) 7. Install shield and washer in drive housing. 74038 Shield Washer 8. Install field frame over armature. Align slot in end cap and field frame for proper position- ing of rubber grommet.

  • Page 322: Pinion Clearance

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 9. Install field frame and end cap in drive housing align slots in field frame with recess in drive housing. Drive Housing End Cap And Field Frame 10. Install through bolts and brush lead. Tighten fasteners securely. Pinion Clearance Pinion clearance must be checked after reassembly of starter motor.
  • Page 323 STARTING SYSTEM SERVICE MANUAL NUMBER 23 4. Push pinion back toward commutator end to eliminate slack. 5. Measure distance between pinion and pinion retainer. 6. If clearance is not within limits of .010-.160 in. (0.25-4.00 mm), it may indicate excessive wear of solenoid linkage, shift lever yoke, or improper assembly of shift lever mecha- nism.

  • Page 324: Installation

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Installation IMPORTANT: Install special mounting shim (if equipped) between starter motor and engine block. 1. Place starter motor in position and install mounting bolts. Torque bolts to 50 lb-ft (68 Nm). 2. Connect yellow/red wire to terminal S of solenoid. Connect orange wire and red wire to fuse terminal.

  • Page 325: Pg260F1 Starter Motor

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 PG260F1 Starter Motor PG260F1 Specifications Delco I.D. Number MerCruiser Part Number 9000839 - 9000840 50-807904 No Load Test Brush Spring Engine Engine Tension Oz. Min. Rotation Volts Max. Amp Min. rpm Max. rpm (Grams) Amps 11.5 3200...
  • Page 326 STARTING SYSTEM SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 4A-35 Downloaded from https://needmanual.com/...

  • Page 327: Exploded View

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Exploded View 74270 Index Page 4A-36 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...

  • Page 328: Starter Motor Repair

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Screw (2) End Frame and Bearing Brush With Holder Armature Field Frame (With Permanent Magnets) Washer Shield Planetary Gears Shaft 10 - Gear 11 - Drive 12 - Collar 13 - Retaining Ring 14 - Trust Collar 15 - Drive Housing...
  • Page 329 STARTING SYSTEM SERVICE MANUAL NUMBER 23 2. Separate end frame from field frame. 3. Remove brush holder from end frame. 4. Remove armature and field frame from drive housing. 5. Pull armature out of field frame. NOTE: Permanent magnets inside field frame will be holding armature in place. 74270 End Frame and Bearing Screws (2)
  • Page 330 STARTING SYSTEM SERVICE MANUAL NUMBER 23 7. Remove the three screws retaining the solenoid. Remove solenoid from drive housing. 74036 Drive Housing Solenoid Screws (3) 8. Remove drive and associated parts from drive housing. 75821 74035 Drive Housing Drive 9. Remove solenoid arm, metal disc and rubber grommet from the drive housing. 75821 Rubber Grommet Metal Disc...

  • Page 331: Cleaning And Inspection

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 10. Remove thrust collar, retaining ring and collar from planetary shaft with drive. 75821 Thrust Collar Retaining Ring (Inside Collar) Collar Planetary Shaft and Drive 11. Remove drive and gear from planetary shaft. 74087 Typical Gear Planetary Gear Shaft Assembly...

  • Page 332: Armature Tests

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Armature Tests TEST FOR SHORTS Check armature for shorts by placing on growler and holding hack saw blade over armature core while rotating armature. If saw blade vibrates, armature is shorted. After cleaning between commutator bars, recheck. If saw blade still vibrates, replace armature. 01440 Hacksaw Blade Armature Core...

  • Page 333: Reassembly

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Reassembly 1. Install brush holder and bearing on armature. 2. Align brush lead grommet with field frame cut-out. Align holes of end frame with holes of brush holder and drive housing. Install end frame on brush holder. Tighten screws securely.
  • Page 334 STARTING SYSTEM SERVICE MANUAL NUMBER 23 4. Assemble drive on shaft assembly as follows: a. Lubricate drive end of shaft assembly with SAE 10W oil. b. Place gear over shaft. c. Slide drive assembly onto shaft with pinion facing outward. d.
  • Page 335 STARTING SYSTEM SERVICE MANUAL NUMBER 23 5. Install the planetary gears on planetary gear shaft assembly. 6. Install solenoid arm, metal disc and rubber grommet in the drive housing. NOTE: Solenoid arm is designed to fit only one way. Do not use force. 75821 Rubber Grommet Metal Disc...
  • Page 336 STARTING SYSTEM SERVICE MANUAL NUMBER 23 9. Install washer and shield in drive housing. 74038 75821 Washer Shield Drive Housing 10. Install field frame over armature. Align slot in field frame with rubber grommet. 75821 Armature Field Frame Slot Rubber Grommet 11.

  • Page 337: Starter Solenoid

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Starter Solenoid TESTING / REPLACEMENT Pinion clearance must be checked after reassembly of starter motor. 1. Disconnect brush lead from solenoid motor and insulate it carefully. 74041 Brush Lead 2. Connect 12 volt battery positive (+) lead to battery terminal and negative (–) lead to frame.

  • Page 338: Installation

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 6. If clearance is not within limits of .010-.160 in. (0.25-4.00 mm), it may indicate excessive wear of solenoid linkage, shift lever yoke, or improper assembly of shift lever mecha- nism. Replace worn or defective parts, since no provision is made for adjusting pinion clearance.

  • Page 339: Mando Starter Motor

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Mando Starter Motor Identification The starter identification number is located as shown. 76257 Identification Number Electrical Circuit Description This is a general description of the positive current flow, from the battery and through the system until the starter motor cranks.
  • Page 340 STARTING SYSTEM SERVICE MANUAL NUMBER 23 Specifications Starter Specifications Engine No Load Test Mando Rotation Brush Spring Tension Oz. (Grams) Min. Max. Min. Max. Number Volts Amps Amps M59601 2800 2900 83-104 (2353-2948) Pinion Clearance .010-.160 (0.25-4.0 mm) Commutator End Frame Gap Battery Cable Recommendations IMPORTANT: Terminals must be soldered to cable ends to ensure good electrical contact.

  • Page 341: Description

    STARTING SYSTEM SERVICE MANUAL NUMBER 23 Description This starter motor is not serviceable. There are not any service replacements parts, includ- ing the solenoid, for this starter. Replace this starter with a complete Delco PG260 Starter. Exploded View Index Page 4A-50 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 342 IGNITION SYSTEM SERVICE MANUAL NUMBER 23 ELECTRICAL SYSTEM Section 4B - Ignition System Table of Contents Specifications ..... . . 4B-2 Tools .

  • Page 343: Specifications

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 Specifications Description Specification Ignition Timing 8 BTDC Firing Order 1-8-4-3-6-5-7-2 Tools Description Part Number Timing Light 91-99379 Timing Tool (Jumper Plug) 91-805747A2 Multi-Meter / DVA Tester 91-99750A1 Mercruiser Special Timing Tool 91-805747A2 Lubricants / Sealants / Adhesives Description Part Number Silicone Dielectric Compound...

  • Page 344: Ignition Control System Components

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 Ignition Control System Components General Precautions CAUTION Avoid personal injury and/or property damage. Listed below are some of the pre- cautions, along with others listed throughout this manual, that you should observe to help ensure an accident-free maintenance experience: Always disconnect battery cables from battery BEFORE working on electrical system to prevent injury to yourself or damage to electrical system.

  • Page 345: Spark Plugs

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 Spark Plugs CHECKING 1. Disconnect spark plug wires (high tension leads) from spark plugs. 74073 Spark Plug Boot NOTE: Use care when removing spark plug wires and boots from spark plugs. Twist the boot 1/2 turn before removing.
  • Page 346 IGNITION SYSTEM SERVICE MANUAL NUMBER 23 4. Inspect each plug individually for badly worn electrodes, glazed, broken or blistered porcelain and replace where necessary. 72734 Porcelain Insulator Insulator - Cracks Often Occur at This Point Shell Proper Gap Side Electrode Center Electrode (When Adjusting Gap - DO NOT Bend) REPLACING IMPORTANT: Tapered seat spark plugs are not interchangeable with non-tapered...

  • Page 347: Spark Plug Wires

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 Spark Plug Wires CHECKING 1. Visually inspect spark plug wires for damage, such as being cracked, cut or oil soaked. 2. Visually inspect spark plug boots for damage. NOTE: Use care when removing spark plug wires and boots from spark plugs. Twist the boot 1/2 turn before removing.

  • Page 348: Distributor Cap

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 d. Push end of high tension wire into coil tower. Position boot over coil tower and wipe off excess insulating compound. 75634 Wire Supports Distributor Terminal Distributor Coil Wire Terminal Coil Tower NOTE: Make sure boot does not come off of tower due to hydraulic air pressure inside boot, caused during installation.

  • Page 349: Distributor Assembly

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 REPLACING IMPORTANT: Use only a distributor cap recommended for Marine application. 1. Install distributor cap by aligning tab in distributor cap with notch on distributor body. Tighten the retaining screws. NOTE: Use care when removing spark plug wires and boots from distributor cap. Twist the boot 1/2 turn before removing.
  • Page 350 IGNITION SYSTEM SERVICE MANUAL NUMBER 23 DISASSEMBLY 72411 Rotor Shaft Assembly Retainer Shield Pickup Coil Pole Piece Screw Module Housing Gasket Tang Washer Washer Gear NOTE: Whenever disassembling distributor, the retainer (d) must be replaced. DO NOT attempt to use old retainer. Index 90-861326--1 MARCH 1999 Page 4B-9...
  • Page 351 IGNITION SYSTEM SERVICE MANUAL NUMBER 23 1. Remove rotor from shaft by lifting or prying straight up. 2. Remove roll pin. 72917 Gear Roll Pin 3. Remove gear, washer and tang washer. 4. Remove shaft assembly from housing. CAUTION Wear eye protection when removing spring steel retainer clips as described in the following steps.
  • Page 352 IGNITION SYSTEM SERVICE MANUAL NUMBER 23 REASSEMBLY NOTE: When mounting ignition module, thoroughly coat bottom of module with Heat Trans- fer Compound. Failure to do so could result in damage to the module. 1. Coat bottom of module and module mounting pad (on housing) with Heat Transfer Com- pound.

  • Page 353: Ignition Coil

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 INSTALLATION NOTE: For correct timing of the distributor, install making certain that all components are aligned as instructed. 1. Align rotor, housing and intake manifold using scribe marks. 2. Slowly lower distributor (with gasket) through intake manifold and into position. If distrib- utor shaft won’t drop into position, back it out and insert a screwdriver into the hole to turn the oil pump drive shaft.

  • Page 354: Ignition Timing

    IGNITION SYSTEM SERVICE MANUAL NUMBER 23 INSTALLATION 1. Install coil bracket with coil to engine bracket using fasteners. 2. Connect high tension coil lead. 72921 Wire Harness Connection High Tension Coil Lead Connection 3. Connect wire harness connectors. Ignition Timing Checking/Adjusting The engine must be at NORMAL OPERATING TEMPERATURE for this adjustment.
  • Page 355 IGNITION SYSTEM SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 4B-14 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 356 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 ELECTRICAL SYSTEM Section 4C - Charging System Table of Contents Mando 65 Amp Alternator ... . 4C-2 Periodic Maintenance ....4C-7 Identification .

  • Page 357: Mando 65 Amp Alternator

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Mando 65 Amp Alternator Identification 72078 Mando 65 Amp Alternator Excitation Wire - PURPLE Sensing Wire - RED/PURPLE Mando Part Number (Hidden In This View) Replacement Parts Warning WARNING Electrical, ignition and fuel system components on your MerCruiser are designed and manufactured to comply with U.S.
  • Page 358 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Tools Description Part Number Bearing Removal and Installation Kit 91-31229A7 Universal Puller Plate 91-37241 Multi-Meter / DVA Tester 91-99750A1 Ammeter (0-100 Amp) Obtain Locally Lubricants / Sealants / Adhesives Description Part Number Quicksilver Liquid Neoprene 92-25711--3 Torque Specifications Fastener Location...
  • Page 359 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Description The alternator has a rotor, which is supported in two end frames by ball bearings, and is driven by a pulley at approximately twice engine speed. The rotor contains a field winding that is enclosed between two multiple-finger pole pieces. The ends of the field winding are connected to two brushes (mounted in the rear end frame) which make continuous sliding (or slipping) contact with the slip rings.
  • Page 360 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Precautions The following precautions MUST BE observed when working on the alternator system. Failure to observe these precautions may result in serious damage to the alternator or alternator system. 1. DO NOT attempt to polarize the alternator. 2.

  • Page 361: Multiple Efi Engine Battery Precautions

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Multiple EFI Engine Battery Precautions SITUATION Alternators: Alternators are designed to charge the battery that supplies electrical power to the engine that the alternator is mounted on. When batteries for two different engines are connected, one alternator will supply all of the charging current for both batteries.

  • Page 362: System Components

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 System Components The alternator system consists of the alternator, battery, the ignition switch and the wiring which connects these components. Refer to wiring diagrams in SECTION 4E. Periodic Maintenance CAUTION Remove all battery cables from battery (before conducting the following check) to prevent accidentally shorting out electrical system.

  • Page 363: Troubleshooting Tests

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 5. While holding adjustment stud at the correct belt tension, tighten 5/8 in. locking nut. 75545 75509 75483 7.4L MPI Shown - All Others Similar Adjustment Stud Locking Nut Alternator Power Steering Pump on Sterndrive Models 6.

  • Page 364: Circuitry Test

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Circuitry Test Perform the following tests, using a 0-20 volt DC voltmeter, to check that all of the circuits between the alternator and the other components within the alternator system are in good condition. OUTPUT CIRCUIT 1.
  • Page 365 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 5. If reading is between 6.0 and 7.0 volts, rotor field circuit probably is open. Remove regu- lator and inspect for worn brushes or dirty slip rings. Replace brushes if less than 1/4 in. (6 mm) long. If brushes and slip rings are in good condition, disassemble and perform rotor test as outlined under “Component Testing - Rotor”...

  • Page 366: Current Output Test

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Current Output Test Perform this test to check if alternator is capable of producing rated current output, using a 0-100 amp DC ammeter. WARNING Be sure that engine compartment is well-ventilated and that there are no gasoline vapors present (during the test) to prevent the possibility of an explosion and/or a fire, should a spark occur.

  • Page 367: Voltage Output Test

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Voltage Output Test Perform this test to determine if voltage regulator is operating correctly, using a 0-20 volt DC voltmeter. IMPORTANT: Battery MUST BE fully charged (1.260 or above specific gravity) to obtain proper voltage reading in this test. If necessary, charge battery with a battery charger or allow engine to run a sufficient length of time to fully charge battery before taking reading.
  • Page 368 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 5. If a voltmeter reading of 14.5 volts or above is now obtained, voltage regulator is faulty and must be replaced. If voltmeter reading is below 14.5 volts, inspect brushes and slip rings for wear, dirt or damage. If brushes and slip rings are good, alternator is faulty internally.

  • Page 369: Exploded View

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Exploded View 72276 Screws (3) 16 - Flat Washer Nut (9) 17 - Screw Flat Washer (4) 18 - Stator Sensing Wire (RED / PURPLE) 19 - Rotor And Slip Ring Excitation Wire (PURPLE) 20 - Retaining Plate Cover...

  • Page 370: Alternator Repair

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Alternator Repair Removal 1. Disconnect negative (–) battery cable from battery. 2. Disconnect wiring harness from alternator. 3. Loosen the 5/8 in. locking nut on the adjustment stud. 4. Turn the adjustment stud and loosen belt. Remove belt. 5.
  • Page 371 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 4. Remove two brush/regulator attaching screws and remove brush/regulator assembly. 72823 Screws Brush / Regulator Assembly Stud Cover Insulator Tie Strap 5. Scribe a mark on rear end frame, stator and front end frame to ensure proper reassembly later.
  • Page 372 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 9. Turn end frame over (stator upward) and remove one Phillips head screw which secures rectifiers to end frame. 72826 Rectifier Assembly Phillips Head Screw 10. Separate stator and rectifier assembly from rear end frame using screwdriver slots. 11.
  • Page 373 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 IMPORTANT: DO NOT clamp vise on rotor pole pieces when removing pulley nut (in next step), as pole pieces may be distorted. 12. Remove pulley retaining nut by clamping pulley in a vise (using an old belt or protective jaws to protect pulley) and turning nut counterclockwise with a wrench.

  • Page 374: Cleaning And Inspection

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Cleaning and Inspection 1. Clean all parts with a clean, soft cloth. DO NOT use solvent, or electrical components may be damaged. 2. Inspect the following parts for wear and damage: a. Brush/regulator assembly - inspect for cracked casing, damaged brush leads, poor brush lead solder connections, weak or broken brush springs or worn brushes.

  • Page 375: Component Testing

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Component Testing ROTOR 1. Test rotor field circuit for opens, shorts or high resistance (Test 1), using an ohmmeter (set on R x1 scale), as follows: 72831 Testing Rotor Field Circuit Test 1 Test 2 a.
  • Page 376 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 2. Test rotor field circuit for grounds (Test 2), using an ohmmeter (set on R x1 scale) as follows: a. Connect one lead of ohmmeter to either slip ring and the other lead to rotor shaft or pole pieces.
  • Page 377 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 RECTIFIER AND DIODE ASSEMBLY NOTE: Failure of any component in tests following will require replacement of entire rectifier assembly. NEGATIVE (–) RECTIFIER IMPORTANT: Rectifier MUST BE disconnected from stator for this test. CAUTION DO NOT use a test instrument with more than a 12 volt source (in the following test), as rectifier may be damaged.
  • Page 378 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 3. Meter should indicate a high or infinite resistance (no meter movement) when connected one way and a low reading when connected the other. If both readings are high or infinite, rectifier is open. If both readings are low, rectifier is shorted. 4.

  • Page 379: Reassembly

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 CONDENSER 1. Using magneto analyzer and accompanying instructions, perform the following con- denser tests: a. Condenser Capacity Test (must be .5 mfd). b. Condenser Short or Leakage Test. c. Condenser Series Resistance Test. 2. Replace condenser if test results are not within specifications. Reassembly 1.
  • Page 380 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 4. Slide fan spacer onto rotor shaft. Install fan, pulley, lockwasher and nut on shaft. Clamp pulley in a vise, using protective jaws or an old oversize V-belt to protect pulley, and torque nut to specifications. Tighten vise only enough to allow tightening of nut, as excessive tightening may distort pulley.
  • Page 381 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 8. Position rear end frame and stator assembly over front end frame and rotor assembly and align scribe marks on each (scribed during disassembly). Hand-press end frames together, then install four screws. Tighten screws securely. 72561 Rear End Frame Stator...
  • Page 382 CHARGING SYSTEM SERVICE MANUAL NUMBER 23 11. Install tie strap to rectifier stud and stud on brush/rectifier assembly. Tighten nuts securely. 72823 Studs Tie Straps 12. Install cover with one phillips head screw and two nuts. Install two leads with nuts. 72963 Phillips Head Screw Nuts (4)

  • Page 383: Installation

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 14. Install pulley (using an old belt or protective jaws to protect pulley) and torque pulley nut to 42 lb-ft (57 Nm). 72828 Old Belt to Protect Pulley Installation 1. Position alternator in mounting bracket and install mounting bolts. Torque to 35 lb-ft (48 Nm).

  • Page 384: Battery Isolator Diagram

    CHARGING SYSTEM SERVICE MANUAL NUMBER 23 Battery Isolator Diagram 72934 Circuit Breaker Harness Connector Alternator Starter Cranking Battery Ground Stud Auxiliary Battery Isolator Disconnect Orange Wire From Alternator Battery Terminal. Splice Sufficient Gauge Wire To The Orange Wire And Connect As Shown. 8 Gauge Minimum Index 90-861326--1 MARCH 1999...
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  • Page 390 INSTRUMENTATION SERVICE MANUAL NUMBER 23 ELECTRICAL SYSTEM Section 4D - Instrumentation Table of Contents Identification ......4D-2 Senders .

  • Page 391: Identification

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Identification NOTE: One of three distinct lines (Series) of Quicksilver gauges may be installed (if equipped with Quicksilver gauges). Aside from different gauge face appearances and styling, the back of the gauges and wiring connections are different as shown. 72746 Back of Commodore and International Series Gauge - Typical 72965...

  • Page 392: Special Information

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Special Information Lighting Options COMMODORE AND INTERNATIONAL SERIES These gauges may be wired so that the illumination lighting is provided from the ignition switch or a separate instrumentation lighting switch. By removing contact strip “I” from between + terminal and the screw as shown following, and supplying a separate +12 V power supply to the screw connection, illumination lights can be operated independent of ignition switch.
  • Page 393 INSTRUMENTATION SERVICE MANUAL NUMBER 23 NOTE: For different lighting effects, colored sleeves are available through the Quicksilver Accessories and can be assembled to the bulb. 72968 Ignition Switch Lighting Circuit Position Positive (+) 12 Volt Power Supply From Ignition Switch 72969 Separate Instrumentation Lighting Circuit Position Positive (+) 12 Volt Power Supply From Ignition...

  • Page 394: Gauges

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Gauges Oil, Fuel and Temperature IMPORTANT: If testing proves gauge to be defective, it must be replaced as there is no repair available. TESTING 1. Turn ignition switch to OFF. 2. Remove wire from terminal S (SEND). 72965 Typical Terminal S (SEND)

  • Page 395: Battery Gauge

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 6. Turn ignition switch to RUN. 7. Indicator needle of gauge being tested must read at position B. If not, replace gauge. 72749 Position B (Typical) Battery Gauge TESTING 1. Remove cables from battery and fully charge battery. 2.

  • Page 396: Cruiselog Meter

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Cruiselog Meter TESTING 1. Connect jumper wire from positive (+) battery terminal to positive (+) gauge terminal. 2. Connect jumper wire from negative (–) battery terminal to negative (–) gauge terminal. 72752 3. Observe gauge run indicator. If indicator is turning, gauge is operable; if not, replace gauge.

  • Page 397: Tachometer

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 CALIBRATION CHART Air Pressure Gauge psi Speedometer Gauge MPH (km/Hr) 20 2 (32 1.6) 27.8 45 1 (72 1.6) Tachometer TESTING 1. Connect a service tachometer to engine and compare readings. 2. Replace if not within specifications. Tachometer Allowance 6000 rpm...

  • Page 398: Senders

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Senders Oil Pressure DUAL STATION SENDER IDENTIFICATION Sender will have 353-AM stamped on hex of sender. TESTING IMPORTANT: Use following test procedure for checking accuracy of oil pressure sender only. If oil pressure gauge indicates zero oil pressure, refer to SECTION 1C “Troubleshooting.”...

  • Page 399: Water Temperature

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Water Temperature DUAL STATION SENDER IDENTIFICATION Sender will have 362-BC stamped on hex. REMOVAL 1. Drain coolant from closed cooling system into a suitable container as outlined in SECTION 6B. 2. Remove TAN wire from temperature sender. NOTE: Hoses are shown removed for clarity.
  • Page 400 INSTRUMENTATION SERVICE MANUAL NUMBER 23 WARNING The following test involves the use of intense heat. Failure to follow appropriate procedures or warnings can cause burns which can result in severe personal injury. While performing the following test, observe these general precautions: Wear personal protective clothing such as rubber gloves, a non-flammable apron, and eye protection - preferably full face shield or safety glasses.

  • Page 401: Fuel Tank Sender

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Water Temperature Ohms Reading 140 F (60 C) 121-147 194 F (90 C) 47-55 212 F (100 C) 36-41 3. Replace sender if ohmmeter readings are other than as shown for each temperature. INSTALLATION 1. Apply Loctite Pipe Sealant with Teflon to threads of temperature sender. 2.
  • Page 402 INSTRUMENTATION SERVICE MANUAL NUMBER 23 4. With float arm in FULL position (arm horizontal), ohmmeter should read 30 ohms (+ 5 ohms). 72755 Ohmmeter Leads Vertical Float Arm 5. With float arm in EMPTY position (arm vertical) meter should read 240 ohms (+ 5 ohms). Sender is defective if not within specifications.
  • Page 403 INSTRUMENTATION SERVICE MANUAL NUMBER 23 4. Connect ohmmeter between fuel capsule terminal and metal portion of capsule housing. 72757 Ohmmeter Leads Capsule Assembly Magnet 5. Turn magnet counterclockwise until fuel capsule indicator reads EMPTY. Ohmmeter should read 240 ohms (+ 5 ohms). 72758 Capsule Reading Empty 6.

  • Page 404: Switches

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Switches Ignition Key Switch TESTING CAUTION Disconnect battery cables from battery before testing ignition key switch with wires still connected to switch. 1. Disconnect battery cables, if testing ignition key switch with wires connected to switch. 2.

  • Page 405: Lanyard Stop Switches

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Lanyard Stop Switches NOTICE For repair procedures on fuel injected engines, refer to Section 5. TESTING 1. Disconnect switch leads. 2. Test switch as follows. a. Connect an ohmmeter to leads. b. There should be continuity with switch lanyard connected and no continuity with switch lanyard disconnected.

  • Page 406: Start/Stop Switch

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Start/Stop Switch TESTING WARNING Disconnect battery leads at battery before testing. 1. Disconnect battery leads. 2. Check for continuity between the terminals on the start switch with a continuity meter. 72763 3. No continuity should exist. 4.

  • Page 407: Oil Pressure Switch

    INSTRUMENTATION SERVICE MANUAL NUMBER 23 Oil Pressure Switch TESTING 1. Remove wire from sender terminal. 2. Connect continuity meter between sender terminal and sender hex. (Sender shown removed for clarity.) 72764 3. With engine not running, meter should indicate full continuity. 4.
  • Page 408 INSTRUMENTATION SERVICE MANUAL NUMBER 23 TESTING 1. Connect one lead of an ohmmeter to one terminal of transmission switch. Connect the other lead of ohmmeter to other terminal. 72771 Ohmmeter Leads Transmission Fluid Temperature Switch 2. Switch should read no continuity. If continuity exists, replace the switch. WARNING The following test involves the use of intense heat.
  • Page 409 INSTRUMENTATION SERVICE MANUAL NUMBER 23 4. Heat sand and observe thermometer. 72772 Suitable Container Thermometer Heat Source Transmission Fluid Temperature Switch Ohmmeter Leads 5. As temperature rises, switch will close and ohmmeter will indicate continuity. Refer to chart below for specifications. Switch Condition Temperature Opens...
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  • Page 412 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 ELECTRICAL SYSTEM Section 4E - Wiring Diagrams Table of Contents Wiring Colors for MerCruiser ..4E-2 MEFI 2 MCM 7.4L MPI (L-29) Model 4E-14 Starting and Charging System Wiring MEFI 2 MIE 7.4L MPI Model .

  • Page 413: Wiring Colors For Mercruiser

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Wiring Colors for MerCruiser NOTE: Color codes listed below DO NOT apply to fuel injection system harnesses. BIA COLOR CODE AND WHERE USED ABBREVIATIONS BLACK (BLK) All Grounds BROWN (BLU) Reference Electrode - MerCathode ORANGE (ORN) Anode Electrode - MerCathode LT.
  • Page 414 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 4E-3 Downloaded from https://needmanual.com/...

  • Page 415: Starting And Charging System Wiring Harness Diagrams

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Starting and Charging System Wiring Harness Diagrams MCM (Sterndrive) 454 / 502 MPI 71693 Index Page 4E-4 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 416 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 A - Charging And Starting System Alternator Ground Stud Starter Motor Battery Circuit Breaker Starter Slave Solenoid B - Audio Warning System Oil Pressure Switch Drive Unit Oil Level Bottle Switch C - Instrumentation System Oil Pressure Sender Water Temperature Sender Trim Sender...
  • Page 417 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MCM (Sterndrive) 7.4L MPI 75467 Index Page 4E-6 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 418 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 A - Charging And Starting System Alternator Ground Stud Starter Motor Circuit Breaker Starter Slave Solenoid B - Audio Warning System Transmission Temperature Switch (If Equipped) C - Instrumentation System Oil Pressure To Sender Trim Sender To Gauge Positive (12V) Power Wire To Fuel Injection System Harness Harness Connector To Fuel Injection System Harness...
  • Page 419 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MIE (Inboard) 454 MPI Horizon & 8.2L MPI 75156 Index Page 4E-8 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 420 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 A - Charging And Starting System Alternator Ground Stud Starter Motor Circuit Breaker Starter Slave Solenoid Neutral Safety Switch B - Audio Warning System Oil Pressure Switch Transmission Fluid Temperature Switch Accessory (Load Must Not Exceed 5 Amps) C - Instrumentation System Oil Pressure Sender Water Temperature Sender...
  • Page 421 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MIE (Inboard) 7.4L MPI 75687 Index Page 4E-10 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 422 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 A - Charging And Starting System Alternator Ground Stud Starter Circuit Breaker Starter Slave Solenoid Neutral Safety Switch B - Instrumentation System Oil Pressure Sender Accessory (Load Must Not Exceed 5 Amps) C - Audio Warning System Transmission Fluid Temperature Switch Positive (12V) Power Wire To Fuel Injection System Harness Harness Connector To Fuel Injection System Harness...

  • Page 423: Fuel Injection Wiring Harness Diagrams

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Fuel Injection Wiring Harness Diagrams MEFI 1 MCM (Sterndrive) 454 / 502 Mag MPI and MIE (Inboard) 454 Mag MPI Horizon and 8.2L MPI Models NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system harness.
  • Page 424 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Fuel Pump Throttle Body Distributor Coil Electronic Spark Control Module Data Link Connector (DLC) Manifold Absolute Pressure (MAP) Sensor Knock Sensor Idle Air Control (IAC) 10 - Throttle Position (TP) Sensor 11 - Engine Coolant Temperature (ECT) Sensor 12 - Electronic Control Module (ECM) 13 -...

  • Page 425: Mefi 2 Mie 7.4L Mpi Model

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MEFI 2 MCM (Sterndrive) 7.4L MPI (L-29) Model NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system harness. 75682 Fuel Pump 13 - Ignition/System Relay Distributor 14 - Fuse (15 Amp) Fuel Pump Fuse (15 Amp) ECM / DLC / Battery Fuse (10 Amp) ECM / Coil Injector / Ignition / Knock Module...
  • Page 426 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MEFI 2 MIE (Inboard) 7.4L MPI Model NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system harness. 75682 Fuel Pump 13 - Ignition/System Relay Distributor 14 - Fuse (15 Amp) Fuel Pump Fuse (15 Amp) ECM / DLC / Battery Fuse (10 Amp) ECM / Coil Injector / Ignition / Knock Module...
  • Page 427 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MEFI 3 MCM (Sterndrive) 454 / 502 Mag MPI and MIE (Inboard) 454 Mag MPI Horizon and 8.2L MPI Models NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system harness.

  • Page 428: Mefi 3 Mcm 7.4L Mpi Bravo And Mie 7.4L Inboard

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MEFI 3 MCM (Sterndrive) 7.4L MPI Bravo and MIE (Inboard) 7.4L Inboard NOTE: All BLACK wires with a ground symbol are interconnected within the EFI system har- ness. NOTE: Component position and orientation shown is arranged for visual clarity and ease of circuit identification.

  • Page 429: Instrumentation Harness Diagrams

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Instrumentation Harness Diagrams MCM (Sterndrive) 74046 Refer to gauge manufacturer’s instructions for specific connections. NOTE: Connect wires together with screw and hex nut. Apply Liquid Neoprene to connec- tion and slide rubber sleeve over connection. NOTE: Power for a fused accessory panel may be taken from this connection.

  • Page 430: Mie (Inboard)

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 MIE (Inboard) 74274 Refer to gauge manufacturer’s instructions for specific connections. NOTE: Connect wires together with screw and hex nut. Apply Quicksilver Liquid Neoprene to connection and slide rubber sleeve over connection. NOTE: Power for a second fused accessory panel may be taken from this connection. Load MUST NOT exceed 40 amps.

  • Page 431: Dual Station Wiring

    WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Dual Station Wiring (Using a Neutral Safety Switch in Only One Remote Control) UNSW SEND SEND SEND YEL/RED RED/PUR BRN/WHT UNSW SEND SEND SEND RED/PUR YEL/RED BRN/WHT YEL/RED YEL/RED 72940 Index Page 4E-20 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 432 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 NOTE: BROWN/WHITE wire is taped back at instrument end. If installing on boat that is equipped with MerCruiser Sterndrive, BROWN/WHITE wire is connected to trim sender terminal block. If installing on MerCruiser Inboard, BROWN/WHITE wire is taped back at engine end, or it may be used for an accessory (limit 5 amperes).
  • Page 433 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Dual Station Wiring (Using A Neutral Safety Switch In Both Remote Controls) UNSW SEND SEND SEND YEL/RED RED/PUR BRN/WHT UNSW SEND SEND SEND RED/PUR YEL/RED YEL/RED BRN/WHT YEL/RED YEL/RED 72941 Index Page 4E-22 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 434 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 NOTE: BROWN/WHITE wire is taped back at instrument end. If installing on boat that is equipped with MerCruiser Sterndrive, BROWN/WHITE wire is connected to trim sender terminal block. If installing on MerCruiser Inboard, BROWN/WHITE wire is taped back at engine end, or it may be used for an accessory (limit 5 amperes).
  • Page 435 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 Dual Station Wiring (Using a Neutral Safety Switch in Engine Wiring Harness) UNSW SEND SEND SEND YEL/RED RED/PUR BRN/WHT UNSW SEND SEND SEND RED/PUR YEL/RED YEL/RED BRN/WHT 72942 Index Page 4E-24 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 436 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 NOTE: BROWN/WHITE wire is taped back at instrument end. If installing on boat that is equipped with MerCruiser Sterndrive, BROWN/WHITE wire is connected to trim sender terminal block. If installing on MerCruiser Inboard, BROWN/WHITE wire is taped back at engine end, or it may be used for an accessory (limit 5 amperes).
  • Page 437 WIRING DIAGRAMS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 4E-26 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 438 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 FUEL SYSTEM Section 5A - Fuel Delivery System For Electronic Fuel Injection Table of Contents Specifications ..... . . 5A-2 Cool Fuel System Repair .

  • Page 439: Specifications

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Specifications Description Specification Pump Pressure (MEFI 1 and MEFI 2) 34-38 PSI (235-262 kPa) Pump Pressure (MEFI 3) 41 - 45 psi (282 - 310 kPa) Fuel Line Vacuum Maximum 2 in Hg (7 kPa) Engine Compartment Pressure Differential 2 in H...

  • Page 440: Fuel Supply Connections

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Fuel Supply Connections WARNING Avoid gasoline fire or explosion. Improper installation of brass fittings or plugs into fuel pump or fuel filter base can crack casting and/or cause a fuel leak. Apply #592 Loctite Pipe Sealant with Teflon to threads of brass fitting or plug.

  • Page 441: Fuel Delivery System

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Fuel Delivery System Recommendations WARNING Boating standards (NMMA, ABYC, etc.) and Coast Guard regulations must be adhered to when installing fuel delivery system. The main concern of a boat’s fuel system is safety; this must be achieved through a techni- cally sound installation and constant inspection.
  • Page 442 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Only a few points related to function and safety are listed here. Refer to boating standards (NMMA, ABYC, etc.) and Coast Guard regulations for complete guidelines. All connections should be on the upper side of the tank. The drain plug at the lowest point on the tank serves to permit the removal of water and sediment.

  • Page 443: Special Tools

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Special Tools Description Tool Name Part Number Minimum 10 megohm input impedance required on all voltage ranges. As High Impedance ammeter, accurately measures low value J-34029-A Multimeter (DVM) current flow. As ohmmeter, reads 0-200 ohms, 2/20/200 kΩ, 2/20 mΩ...

  • Page 444: Rinda Technologies Special Tools

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Rinda Technologies Special Tools Description Tool Name Part Number Rinda Technologies 4563 N. Elston Ave. Chicago, IL 60630 Phone: 773-736-6633 Displays problem codes stored in the ECM. It also allows monitoring of various EFI Scan Tool/Injec- circuits and components in the fuel 94040M...

  • Page 445: Cool Fuel System Exploded View

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Cool Fuel System Exploded View 75708 Index Page 5A-8 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 446 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Exploded View Component List Bracket Cover Base Screw and Washer (2) Fuel Pressure Regulator Return Fuel Line Retaining Ring O-Rings (2) Fuel Line To Fuel Rail Gasket 10 - Drain Plug 11 - Stepped Screw...

  • Page 447: Fuel System Flow Diagram

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Fuel System Flow Diagram 74871 Vacuum Line To Plenum Fuel Pressure Regulator Fuel Cooler Electric Fuel Pump Water Separating Fuel Filter Fuel Line from Tank Direction Of Water Flow Fuel Line to Fuel Pump Fuel Line To Fuel Rail Excess Fuel Return Line To Water Separating Fuel Filter...

  • Page 448: Water Separating Fuel Filter

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Water Separating Fuel Filter NOTICE Refer to “Precautions” in this section, BEFORE proceeding. MCM Model Shown Top Cover (MCM Models Only) Insulator Plate Fuel Return Line from Regulator Brass Fitting Fuel Line to Fuel Pump Brass Fitting Fuel Filter Mounting Bracket...

  • Page 449: Cool Fuel System Repair

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Cool Fuel System Repair Removal 1. Disconnect battery cables from battery. IMPORTANT: Suitably plug open ends of fuel line connections to prevent fuel leaks and entry of water or contaminates into lines while working. 2.

  • Page 450: Disassembly

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 15. Carefully remove the cool fuel system assembly. 16. Slide fuel injectors from their respective bores of intake manifold until fuel rail and injec- tors are free. Remove fuel rail and injectors as an assembly. NOTE: The fuel injectors are to remain fully seated in the fuel rail throughout removal.
  • Page 451 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 4. Install the fuel rail fuel line following appropriate procedure: Procedure A 1. Install fuel cooler-to-fuel rail line as follows: a. Install two (of six) O-rings onto the cooler-to-fuel rail fuel line where it attaches to the cooler, if not already present on the line.
  • Page 452 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 IMPORTANT: To prevent loss of the stepped screw used to secure the cooler-to-fuel rail fuel line, a retainer ring is provided. Do not remove the retainer or stepped screw. 75708 Fuel Line O-Rings Fuel Line, Cooler-to-Fuel Rail...

  • Page 453: Installation

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Installation 1. If removed, reinstall the fuel filter assembly and secure using the two self locking nuts. Tighten the nuts securely. 2. Connect the fuel lines to the fuel filter adapter. Tighten securely. 75533 Filter Assembly Fuel Lines...
  • Page 454 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 MEFI 2 FUEL COOLER TO FUEL RAIL LINE INSTALLATION 5. On 7.4L MPI: Install the cooler-to-fuel rail line as follows: a. Route the fuel line to the back side of engine. b.
  • Page 455 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 MEFI 3 FUEL COOLER TO FUEL RAIL LINE INSTALLATION 1. Install fuel cooler-to-fuel rail line as follows: a. Install two new O-rings on fuel inlet line. b. Lubricate both O-rings with a small amount of liquid soap. c.
  • Page 456 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 d. Install the fuel pump with elbow fitting in the cooler assembly. 75708 O-Rings (4) Elbow Fitting Fuel Pump Fuel Cooler 4. Position the completed fuel cooler assembly in the cover base. 5.

  • Page 457: Vacuum Line Routing

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 Vacuum Line Routing 454/502 MPI and 8.2L MPI Models With MEFI 1 75739 Plenum Cool Fuel Assembly Vacuum Hose - T-Fitting to Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - Valve Cover to Throttle Body Flame Arrestor Vent Hose - Front of Plenum to PCV Valve Vacuum Hose - Fuel Pressure Damper to T-Fitting...

  • Page 458: 454/502 Mpi And 8.2L Mpi Models With Mefi 3

    FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 454/502 MPI and 8.2L MPI Models With MEFI 3 75739 Plenum Cool Fuel Assembly Vacuum Hose - Fuel Pressure Regulator on Cool Fuel Assembly-to-Plenum Vent Hose - Valve Cover to Throttle Body Flame Arrestor Vent Hose - Front of Plenum to PCV Valve PCV Valve Front of Engine...
  • Page 459 FUEL DELIVERY SYSTEM FOR ELECTRONIC FUEL INJECTION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5A-22 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 460 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 FUEL SYSTEM Section 5B - Multi-Port Fuel Injection Descriptions And System Operation Table of Contents Identification ......5B-2 Electronic Control Module (ECM) and Electronic Control Module (ECM)

  • Page 461: Identification

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Identification Electronic Control Module (ECM) 72801 MEFI-1 and MEFI-2 ECM 76077 MEFI-3 ECM Model Serial Number ECM Type MCM 7.4L (L29) 0L01003-0L085013 MEFI-2 MCM 7.4L (L29) 0L085014-and Above MEFI-3 MIE 7.4L (L29) 0L002006-0L086199 MEFI-2...

  • Page 462: General Information

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 General Information CAUTION To reduce the chance of personal injury and/or property damage, the following instructions must be carefully observed: proper service and repair are important to the safety of the service technician and the safe, reliable operation of all MerCruiser Electronic Fuel Injection (Multi-Port And Throttle Body) equipped engines.

  • Page 463: Electrostatic Discharge Damage

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Electrostatic Discharge Damage Electronic components used in control systems are often designed to carry very low voltage, and are very susceptible to damage caused by electrostatic discharge. It is possible for less than 100 volts of static electricity to cause damage to some electronic components.

  • Page 464: Wiring Connector Service

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 WIRE REPAIR 1. Locate damaged wire. 2. Remove insulation as required. 73048 3. Splice two wires together using splice clips and rosin core solder. 73048 4. Cover splice with heat shrink sleeve to insulate from other wires. 73048 Wiring Connector Service Most connectors in the engine compartment are protected against moisture and dirt which...

  • Page 465: Abbreviations

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Abbreviations BARO Barometric Pressure Battery Positive Terminal, Battery or System Voltage Battery Positive Circuit CONN Connector Cylinder Degrees DIAG Diagnostic DIST Distributor Data Link Connector Diagnostic Trouble Code DVOM Digital Volt Ohm Meter Engine Control Module Engine Coolant Temperature...

  • Page 466: Ecm Self-Diagnostics

    Volts Vacuum Wide Open Throttle in-hg Inches Of Mercury ECM Self-Diagnostics The ECM performs a continual self-diagnosis on certain control functions. This diagnostic capability is complemented by the diagnostic procedures contained in this manual. The ECM’s language for communicating the source of a malfunction is a system of diagnostic codes.

  • Page 467: Intermittent Malfunction Indicator Lamp

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Intermittent Malfunction Indicator Lamp In the case of an intermittent problem, the Malfunction Indicator Lamp will light for ten seconds and then will go out. However, the corresponding code will be stored in the memory of the ECM.

  • Page 468: Scan Tools

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 SERVICE MODE When the diagnostic code tool is installed at the Data Link Connector (DLC) and the selector switch is set at SERVICE, the system will enter what is called the SERVICE mode. In this mode the ECM will: 1.

  • Page 469: Scan Tool Use With Intermittents

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Scan Tool Use With Intermittents The scan tool allows manipulation of wiring harnesses or components with the engine not running, while observing the scan tool readout. The scan tool can be plugged in and observed while running the vessel under the condition when the Malfunction Indicator Lamp turns ON momentarily or when the engine driveability is momentarily poor.

  • Page 470: Non-Scan Diagnosis Of Driveability Concerns (With No Codes Set)

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 CLEARING CODES USING SCAN TOOL (SCAN) 1. Connect scan tool. 2. Start engine. 3. Select clear codes function. 4. Clear codes. 5. Turn key OFF. 6. Turn key ON and read codes. If codes are still present, (there is a real fault in system) check following note and repeat Step 1.

  • Page 471: Special Tools

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Special Tools Description Tool Name Part Number Minimum 10 megohm input impedance required on all voltage ranges. As amme- High Impedance J-34029-A ter, accurately measures low value current Multimeter (DVM) flow.

  • Page 472: Precautions

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Precautions The following requirements must be observed: Before removing any ECM system component, disconnect the negative battery cable. Never start the engine without the battery being solidly connected. Never separate the battery from the on-board electrical system while the engine is run- ning.
  • Page 473 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 When a test light is specified, a “low-power” test light must be used. DO NOT use a high- wattage test light. While a particular brand of test light is not suggested, a simple test, as shown below, on any test light will ensure it to be safe for system circuit testing.

  • Page 474: Electronic Control Module (Ecm) And Sensors

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Electronic Control Module (ECM) and Sensors General Description The MerCruiser Electronic Fuel Injection system is equipped with a computer that provides the operator with state-of-the-art control of fuel and spark delivery. Computers use voltage to send and receive information.

  • Page 475: Digital Signals

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 TWO-WIRE SENSORS (ECT AND IAT) The following figure is the schematic of a 2-wire type sensor. This sensor is basically a variable resistor in series with a fixed-known resistor within the computer. By knowing the values of the input voltage and the voltage drop across the known resistor, the value of the variable resistor can be determined.
  • Page 476 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 The computer uses digital signals in a code that contains only ones and zeros. The high volt- age of the digital signal represents a one (1), and no voltage represents a zero (0). Each zero and each one is called a bit of information, or just a “bit.”...

  • Page 477: Engine Control Module (Ecm)

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Engine Control Module (ECM) The Engine Control Module (ECM) is the control center of the fuel injection system. It constantly monitors information from various sensors, and controls the systems that affect engine performance.

  • Page 478: Speed Density System

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Speed Density System The Electronic Fuel Injection system is a speed and air density system. The system is based on “speed/density” fuel management. Three specific data sensors provide the ECM with the basic information for the fuel manage- ment portion of its operation.

  • Page 479: Ecm Input And Sensor Descriptions . 5B-20

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 ECM Input and Sensor Descriptions The following lists the sensors, switches, and other inputs used by the ECM to control its various systems. Although we will not cover them all in great detail, there will be a brief description of each.
  • Page 480 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 ENGINE COOLANT TEMPERATURE (ECT) SENSOR The Engine Coolant Temperature (ECT) Sensor is a thermistor (a resistor which changes value based on temperature) immersed in the engine coolant stream. Low coolant tempera- ture produces a high resistance, while high temperature causes low resistance.
  • Page 481 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR The Manifold Absolute Pressure (MAP) sensor is a pressure transducer that measures the changes in the intake manifold pressure. The pressure changes as a result of engine load and speed change, and the MAP sensor converts this to a voltage output.
  • Page 482 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 KNOCK SENSOR (KS) MODULE (MEFI 1 AND MEFI 2 MODELS ONLY) When the key switch is turned on, 12 volts are supplied to the KS module B terminal through the system relay.
  • Page 483 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 THROTTLE POSITION (TP) SENSOR The Throttle Position (TP) Sensor is a potentiometer connected to the throttle shaft on the throttle body. The TP has one end connected to 5 volts from the ECM and the other to ECM ground.

  • Page 484: Engine Control Module (Ecm) And Delco Est Distributor System

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Engine Control Module (ECM) and Delco EST Distributor System The Delco EST Distributor operates independent of the ECM. Dwell time and spark advance are controlled by the ECM. Voltage signals between the two are processed by the Ignition Control (IC) module inside the distributor.
  • Page 485 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 The ECM controls the primary current going to the ignition coil. It sends a voltage signal to the IC module that sends a voltage signal to the ignition coil. This signal will trigger the coil creating secondary spark to be produced.

  • Page 486: Spark Management

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Spark Management High Energy Ignition with Ignition Control (IC) The Electronic Fuel Injection is controlled by an Engine Control Module (ECM). This module is the nerve/decision center of the system. It uses all the information it gathers to manage ignition spark, delivering increased fuel economy and maximum engine performance.
  • Page 487 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5B-28 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 488 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Distributor Module Mode The following describes IC operation during cranking and when the engine starts running. During cranking, the relay is in the de-energized position (see figure “Distributor Module Mode”), preceding.

  • Page 489: Base Ignition Timing

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Base Ignition Timing In order to check or change base timing on a HEI system the ECM has to be entered into the service mode by using a scan tool or code tool. The IC module will go to base timing. The ECM will stabilize timing to allow timing adjustment.
  • Page 490 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Ignition Coil Trigger Signal Battery Relay Module Advance Signal Converter Pick Up Coil Ground Manifold Coolant Temperature REF HI Bypass REF LO Grounded No Voltage Applied Not Grounded Voltage Applied Index 90-861326--1 MARCH 1999 Page 5B-31...

  • Page 491: Results Of Incorrect Operation

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Results of Incorrect Operation Open IC Line from the ECM to the Distributor Module - While the engine is cranking, the ECM expects to see the IC signal pulled to virtually zero because it is grounded in the distrib- utor module.

  • Page 492: Fuel Metering System

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 Fuel Metering System General Description The function of the fuel metering system is to deliver the correct amount of fuel to the engine under all operating conditions. The fuel is delivered to the engine by individual fuel injectors mounted in the intake manifold near each cylinder.
  • Page 493 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 ACCELERATION MODE The ECM looks at rapid changes in Throttle Position (TP) and provides extra fuel by increas- ing the injector pulse width. FUEL CUTOFF MODE No fuel is delivered by the injectors when the ignition is OFF, to prevent dieseling. Also, fuel pulses are not delivered if the ECM receives no distributor reference pulses, which means the engine is not running.

  • Page 494: 454/502 Mag Mpi And 8.2L Mpi Multi-Port Injection Components

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 454/502 Mag MPI and 8.2L MPI Multi-Port Injection Components FUEL PUMP ELECTRICAL CIRCUIT When the ignition switch is turned to the RUN position, the ECM will turn ON the fuel pump relay for two (2) seconds.
  • Page 495 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 FUEL INJECTORS The EFI injector assembly is a solenoid-operated device, controlled by the ECM, that meters pressurized fuel to a single engine cylinder. The ECM grounds the injector solenoid, which opens a pintle valve, allowing fuel to flow past the pintle valve.
  • Page 496 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 FUEL PRESSURE REGULATOR ASSEMBLY MEFI 1 and MEFI 2 Only: The pressure regulator is a diaphragm-operated relief valve with fuel pump pressure on one side, and regulator spring pressure and intake manifold vacuum on the other.
  • Page 497 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 IDLE AIR CONTROL (IAC) VALVE The purpose of the IAC valve assembly is to control engine idle speed, while preventing stalls due to changes in engine load. The IAC valve, mounted in the throttle body, controls bypass air around the throttle valves.

  • Page 498: 7.4L Mpi Multi-Port Injection Components

    MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 7.4L MPI Multi-Port Injection Components FUEL PUMP ELECTRICAL CIRCUIT When the ignition switch is turned to the RUN position, the ECM will turn ON the fuel pump relay for two (2) seconds. When the ignition switch is turned to the crank position, the ECM turns the fuel pump relay ON causing the fuel pump to start.
  • Page 499 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 FUEL PRESSURE REGULATOR ASSEMBLY The pressure regulator is a diaphragm-operated relief valve with fuel pump pressure on one side, regulator spring pressure and intake manifold vacuum on the other. The regulator’s function is to maintain a constant pressure differential across the injectors at all times.
  • Page 500 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 IDLE AIR CONTROL (IAC) VALVE The purpose of the IAC valve assembly is to control engine idle speed, while preventing stalls due to changes in engine load. The IAC valve, mounted on the throttle body, controls bypass air around the throttle valves.
  • Page 501 MULTI-PORT FUEL INJECTION DESCRIPTIONS AND SYSTEM OPERATION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5B-42 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 502 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 FUEL SYSTEM Section 5C - Multi-Port Fuel Injection Disassembly And Reassembly Table of Contents Precautions ......5C-2 Idle Air Control (IAC) Valve .

  • Page 503: Precautions

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Precautions WARNING Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion. WARNING Be careful when cleaning flame arrestor and crankcase ventilation hose; gasoline is extremely flammable and highly explosive under certain conditions.

  • Page 504: Exploded Views

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Exploded Views 454/502 Mag MPI and 8.2L MPI Flame Arrestor and Throttle Body 72800 Cap Nut Flame Arrestor (All Models Except Horizon) Stud Throttle Body Gasket Throttle Position (TP) Sensor Washer Screw O-Ring...

  • Page 505: 454/502 Mag Mpi And 8.2L Mpi Plenum

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 454/502 Mag MPI and 8.2L MPI Plenum 72802 Screw Screw Plenum Sleeve Drain Line To Intake Manifold Bracket Stud Screw 10 - Intake Air Temperature (IAT) Sensor 11 - Gasket 12 - Seal 13 -...
  • Page 506 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5C-5 Downloaded from https://needmanual.com/...

  • Page 507: 454/502 Mag Mpi And 8.2L Mpi Intake Manifold And Fuel Rail

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 454/502 Mag MPI and 8.2L MPI Intake Manifold and Fuel Rail 75741 Index Page 5C-6 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 508 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Intake Manifold Bolt Washer Bolt Retainer Fuel Rail Bolt Filter O-Ring 10 - Fuel Damper 11 - Plug 12 - Bolt 13 - 14 - Schrader Valve 15 - Engine Coolant Temperature (ECT) Sensor 16 - Plug 17 -...

  • Page 509: Fuel Pressure Relief Procedure

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Fuel Pressure Relief Procedure NOTICE Refer to “Precautions” in this section, BEFORE proceeding. 1. Disconnect electrical connector at fuel pump. 2. Crank engine for ten seconds (if engine starts allow it run until it stops) to relieve any fuel pressure in the system.

  • Page 510: Throttle Body

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Throttle Body NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove four flame arrestor mounting cap nuts and remove flame arrestor from throttle body. 72790 Flame Arrestor Cap Nuts (4) 2.
  • Page 511 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 4. Turn throttle body as shown and disconnect TP sensor, drain tube and IAC electrical connectors. 72793 Throttle Body Throttle Position (TP) Sensor Idle Air Control (IAC) Valve Drain Tube IMPORTANT: To prevent damage to throttle valve, it is essential that throttle body be placed on a holding fixture before performing service.
  • Page 512 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 CLEANING AND INSPECTION IMPORTANT: DO NOT use cleaners containing methyl ethyl ketone. It is not neces- sary for cleaning throttle bore and valve deposits. IMPORTANT: DO NOT allow the TP sensor and IAC valve to come into contact with solvent or cleaner.
  • Page 513 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 2. Apply Loctite 242 to threads of studs. Using a stud driver, torque studs to 165 lb-in. (18.6 Nm). 72792 Throttle Body Throttle Body Mounting Studs NOTE: If Boat is equipped with Quicksilver Zero Effort Controls, the throttle cable mounting stud must be in the most forward position on throttle lever.

  • Page 514: Plenum

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 4. Install flame arrestor on throttle body. Apply Loctite 242 to threads of studs. Install four flame arrestor mounting cap nuts. Torque cap nuts to 50 lb-in. (6 Nm). 72790 Flame Arrestor Cap Nuts (4) Plenum...
  • Page 515 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 4. Remove twelve plenum mounting fasteners and lift straight up from intake manifold. Turn plenum slightly and rest on intake manifold as shown. Disconnect drain line at plenum and remove plenum. 72797 Plenum Intake Manifold...
  • Page 516 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Install one gasket onto each of the four intake manifold trumpets. 2. Rest plenum on intake manifold as shown. Connect drain line at plenum. Lower plenum evenly onto intake manifold and install twelve plenum mounting fasteners. Torque fasteners to 150 lb-in.

  • Page 517: 454 / 502 Mag Mpi And 8.2L Mpi Fuel Rail And Injectors

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 454 / 502 Mag MPI and 8.2L MPI Fuel Rail and Injectors NOTICE Refer to “Precautions” in this section, BEFORE proceeding. FUEL COOLER-TO-FUEL RAIL LINE (MEFI 3) There are several differences in fuel cooler to fuel rail lines in MEFI 3 models. Refer to SEC- TION 5A for complete instructions.
  • Page 518 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 5. When facing front of engine, remove fuel rail as follows: NOTE: The left bank fuel injectors are to remain fully seated in the fuel rail throughout removal, while the right bank fuel injectors are to remain fully seated in the intake manifold throughout removal.
  • Page 519 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 c. Working from rear of engine to front, insert the first rear left bank fuel injector into the intake manifold. Next, insert the first rear right bank fuel injector into the fuel rail. Continue inserting fuel injectors into their respective bores working back and forth toward front of engine until all fuel injectors are in place.

  • Page 520: Fuel Pressure Damper

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Fuel Pressure Damper NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove flame arrestor, throttle body, plenum and fuel rail as outlined in this section. 2. Remove fuel pressure damper attaching screws and nuts. Remove damper. Ensure that fuel return passage plug is not left in hole.

  • Page 521: 454 / 502 Mag Mpi And 8.2L Mpi Fuel Injectors

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 454 / 502 Mag MPI and 8.2L MPI Fuel Injectors NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL NOTE: Use care in removing fuel injectors to prevent damage to the electrical connector and nozzle.
  • Page 522 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 CLEANING AND INSPECTION Inspect fuel injectors for damage; replace if necessary. INSTALLATION IMPORTANT: When replacing injectors, be certain to replace with the identical part and part number. Other injectors may have the same appearance, yet have a different part number and be calibrated for a different flow rate.

  • Page 523: 454 / 502 Mpi And 8.2L Mpi - Sensor And Module Servicing

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 454 / 502 MPI and 8.2L MPI - Sensor and Module Servicing Precautions WARNING BEFORE attempting to disconnect and remove any module or sensor, check to make sure that the engine ignition system is OFF. Then disconnect the negative (–) battery cable from the terminal.
  • Page 524 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 CLEANING AND INSPECTION 1. Clean the exterior of the ECM with a dry cloth being careful to avoid contact with connector pins. 2. Inspect outer surfaces for damage. 3. Visually inspect electrical pins at both ends of ECM for straightness and corrosion. 4.

  • Page 525: Knock Sensor (Ks) Module

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Knock Sensor (KS) Module NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove Knock Sensor from electrical bracket. 72801 Typical Electrical Bracket Knock Sensor (KS) Module 2. Disconnect electrical connector at Knock Sensor (KS) module. CLEANING AND INSPECTION 1.
  • Page 526 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Connect electrical connector to the Knock Sensor (KS) module. 2. Mount KS module to electrical bracket. 72801 Typical Electrical Bracket Knock Sensor (KS) Sensor Index 90-861326--1 MARCH 1999 Page 5C-25 Downloaded from https://needmanual.com/...

  • Page 527: Engine Coolant Temperature (Ect) Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Engine Coolant Temperature (ECT) Sensor NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL NOTE: Handle the ECT carefully, as any damage to it will affect operation of the system. 1.

  • Page 528: Manifold Absolute Pressure (Map) Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Manifold Absolute Pressure (MAP) Sensor NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Disconnect electrical connector at Manifold Absolute Pressure (MAP) sensor. 72802 Plenum Manifold Absolute Pressure (MAP) Sensor Screws Seal 2.

  • Page 529: Throttle Position (Tp) Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Throttle Position (TP) Sensor NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove flame arrestor, throttle cable and throttle body as outlined in “Throttle Body”. 72800 Throttle Body Throttle Position (TP) Sensor Screws With Lockwashers O-Ring...

  • Page 530: Intake Air Temperature (Iat) Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Install TP sensor on throttle body using screws with lock washers and Loctite 242 ap- plied to threads. Torque screws to 20 lb. in (2 Nm). 72800 Throttle Body Throttle Position (TP) Sensor Screws With Lockwashers O-Ring...

  • Page 531: Idle Air Control (Iac) Valve

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Install IAT sensor in plenum. Tighten 2-1/2 turns maximum. 72802 Plenum Intake Air Temperature (IAT) Sensor 2. Install plenum, throttle body, throttle cable and flame arrestor as outlined in “Plenum”. 3.
  • Page 532 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 CLEANING AND INSPECTION 1. Remove and discard sealing O-ring from IAC valve. Clean sealing surfaces, pintle valve seat, and air passage with a carburetor cleaner to remove carbon deposits, being care- ful not to push or pull on the IAC valve pintle.

  • Page 533: Knock Sensor (Ks)

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Knock Sensor (KS) NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Disconnect electrical connector at knock sensor located just ahead of starter motor. 72846 Knock Sensor 2. Remove knock sensor from engine block. CLEANING AND INSPECTION 1.

  • Page 534: Fuel Pump Relay

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Fuel Pump Relay NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove fuel pump relay from electrical bracket. 72801 Electrical Bracket Fuel Pump Relay 2. Disconnect electrical connector and remove fuel pump relay. IMPORTANT: The fuel pump relay is an electrical component.

  • Page 535: Electrical Box Exploded View

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Electrical Box Exploded View 72801 Electrical Bracket Relay Relay Screw Knock Sensor (KS) Module Screw Slave Solenoid Circuit Breaker 10 - Screw 11 - Screw 12 - MerCathode Controller 13 - Data Link Connector (DLC) 14 - Fuse...

  • Page 536: Vacuum Line Routing

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Vacuum Line Routing 454 / 502 MPI and 8.2L MPI Models 75739 Plenum Cool Fuel Assembly Vacuum Hose - T-Fitting to Fuel Pressure Regulator on Cool Fuel Assembly Vent Hose - Valve Cover to Throttle Body Flame Arrestor Vent Hose - Front of Plenum to PCV Valve Vacuum Hose - Fuel Pressure Damper to T-Fitting Vacuum Hose - T-Fitting to Plenum...

  • Page 537: Exploded View

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Exploded View 7.4L MPI Intake Manifold, Plenum and Fuel Rail 75730 Index Page 5C-36 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 538 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Starboard Engine Cover Port Engine Cover Engine Cover Screws (4) Plenum Plenum Screws (8) Plenum Gaskets (2) Adapter Studs (3) Adapter Gasket Fuel Injector Harness 10 - Fuel Rail Screws 11 - Fuel Rail Stud 12 -...

  • Page 539: 7.4L Mpi Throttle Body And Adapter Components

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 7.4L MPI Throttle Body and Adapter Components 75731 Throttle Body Throttle Body Gasket Throttle Body Adapter Hose Fittings (2) Crankcase Vent Hose Throttle Cable Bracket Screw Anchor Stud 10 - Washer 11 - 12 -...

  • Page 540: Fuel Pressure Relief Procedure

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Fuel Pressure Relief Procedure NOTICE Refer to “Precautions” in this section, BEFORE proceeding. 1. Disconnect electrical connector at fuel pump. 2. Crank engine for ten seconds (if engine starts allow it run until it stops) to relieve any fuel pressure in the system.

  • Page 541: Throttle Body

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Throttle Body NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Remove the flame arrestor from the throttle body. 2. Disconnect the throttle linkage from the throttle body. 75454 Throttle Cable Throttle Lever...

  • Page 542: Plenum

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Place the throttle body gasket between the throttle body and the adapter. 2. Place the throttle body on the adapter. Install the screws and torque to 75 lb-in. (8.5 Nm). 3.
  • Page 543 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 5. Disconnect the wiring harness from the intake air temperature sensor (IAT). 75658 Intake Air Temperature (IAT) Sensor Breather Hose 6. Remove the plenum from the manifold. 75615 Plenum Intake Manifold Screws IMPORTANT: Place a clean shop towel over the openings to prevent foreign materials from entering the engine.
  • Page 544 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Place new gaskets on the manifold. 2. Place plenum over the manifold and install the screws. Torque screws to 30 lb-ft (40 Nm). 75669 Screw (8) Plenum Gasket Intake Manifold 3.

  • Page 545: Fuel Rail And Fuel Injectors

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Fuel Rail and Fuel Injectors NOTICE Refer to “Precautions” in this section, BEFORE proceeding. REMOVAL 1. Relieve fuel pressure from the fuel rail. as previously described. 2. Remove the fuel line from the fuel rail. 3.
  • Page 546 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 8. Remove the retainer clip from the fuel injector. 9. Remove the fuel injector from the fuel rail. 75614 Injector Harness Fuel Injector Retainer Clip CLEANING AND INSPECTION Inspect fuel injectors for damage; replace if necessary. INSTALLATION IMPORTANT: When replacing injectors, be certain to replace with the identical part and part number.
  • Page 547 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 2. Place the retaining clip over the fuel injector. 75672 Fuel Rail Retainer Clip Fuel Injector 3. Connect the injector harness to the fuel injector. 4. Lubricate all of the o-rings on the fuel rail and carefully place them in the intake manifold. 5.

  • Page 548: Map Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Map Sensor NOTICE Refer to “Precautions” in this section, BEFORE proceeding. 1. Relieve fuel pressure from the fuel rail as previously described. 2. Disconnect the fuel line from the fuel rail. 3.

  • Page 549: Throttle Position Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Throttle Position Sensor NOTICE Refer to “Precautions” in this section, BEFORE proceeding. 1. Remove the cover from the starboard side of the engine. 75644 Starboard Engine Cover 2. Remove the flame arrestor from the throttle body. 3.

  • Page 550: Intake Air Temperature (Iat) Sensor 5C-49

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Apply Loctite 242 to the threads. Install the TP sensor to the throttle body using the screws. Torque screws to 20 lb-in. (2 Nm). 75657 Screw (2) Throttle Position (TP) Sensor Throttle Body 2.

  • Page 551: Idle Air Control (Iac) Valve

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 CLEANING AND INSPECTION 1. Clean and inspect surfaces of IAT sensor with a dry cloth. 2. Inspect IAT sensor for signs of wear and/or damage. INSTALLATION 1. Install the IAT sensor in the plenum. TIGHTEN 2-1/2 TURNS MAXIMUM. 75658 Intake Air Temperature IAT Sensor 2.
  • Page 552 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 CLEANING AND INSPECTION 1. Remove and discard sealing O-ring from IAC valve. Clean sealing surfaces, pintle valve seat, and air passage with a carburetor cleaner to remove carbon deposits, being care- ful not to push or pull on the IAC valve pintle.

  • Page 553: Knock Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Knock Sensor NOTICE Refer to “Precautions” in this section, BEFORE proceeding. NOTE: The 7.4L MPI has a knock sensor mounted on the port and starboard sides of the engine block. REMOVAL 1.

  • Page 554: Knock Sensor Module

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 1. Install knock sensors in engine block. Torque to 12-16 lb-ft (16.3-21.7 Nm). 75678 Starboard Side Shown Knock Sensor 2. Connect electrical connector to knock sensors. Knock Sensor Module 1. Remove the knock sensor module from the rear starboard side side of engine. 75656 Shown With Power Steering Cooler Hose Removed Knock Sensor Module...

  • Page 555: Fuel Pump Relay

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 Fuel Pump Relay REMOVAL 1. Remove fuel pump relay from electrical bracket. 75442 Fuel Pump Relay 2. Disconnect electrical connector and remove fuel pump relay. IMPORTANT: The fuel pump relay is an electrical component. DO NOT soak in any liquid cleaner or solvent;...

  • Page 556: Engine Coolant Temperature (Ect) Sensor

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 CLEANING AND INSPECTION 1. Clean the exterior of the ECM with a dry cloth being careful to avoid contact with connec- tor pins. 2. Inspect outer surfaces for any obvious damage 3.

  • Page 557: Vacuum Line Routing

    MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 INSTALLATION 1. Install ECT sensor in intake manifold. TIGHTEN HAND TIGHT PLUS 2-1/2 TURNS MAXIMUM. 75671 75484 Engine Coolant Temperature (ECT) Sensor Harness Connector 2. Connect electrical connector to ECT sensor. Vacuum Line Routing 7.4L MPI Models 75728...
  • Page 558 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5C-57 Downloaded from https://needmanual.com/...
  • Page 559 MULTI-PORT FUEL INJECTION DISASSEMBLY AND REASSEMBLY SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5C-58 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 560 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING FUEL SYSTEM Section 5D - Fuel Injection System Troubleshooting Table of Contents Troubleshooting ..... 5D-2 Visual/Physical Check .

  • Page 561: Troubleshooting

    FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Troubleshooting Diagnostic Trouble Codes for the MEFI 1 454 / 502 Mag MPI and 8.2L MPI Engines Code Number Code Description Code 14 (ECT) Engine Coolant Temperature Code 21 (TP) Throttle Position Sensor Code 23 (IAT) Intake Air Temperature Code 33...
  • Page 562 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Diagnostic Trouble Codes for the MEFI 3 454 cid (7.4L) / 502 cid (8.2L) Engines Code Connection Conditions Comments Number Minimum run time (10 sec) Open circuit ECT high Sensor output high (cold) > 240 Faulty sensor counts Minimum run time (10 sec) sensor...
  • Page 563 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Diagnostic Trouble Codes for the MEFI 3 454 cid (7.4L) / 502 cid (8.2L) Engines (continued) Code Connection Conditions Comments Number Open secondary Ignore first 20 spark events requires wire Coil driver fault 8 faults to set code Open primary cable Checksum error Reserved - Invalid ECM checksum...

  • Page 564: Scan Tool Normal Specifications

    SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Scan Tool Normal Specifications (Idle / Warm Engine / Closed Throttle / Neutral) SCAN POSITION UNITS DISPLAYED TYPICAL DATA VALUE 600-700 rpm Desired rpm 600 rpm Coolant Temp. F( C) 150-170 F (66-77 C) Varies with Ambient Tempera- Manifold Air Temp.

  • Page 565: Important Preliminary Checks

    FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Important Preliminary Checks BEFORE STARTING Before using this section you should have performed the “On-Board Diagnostic (OBD) Sys- tem Check” in in the “General System Diagnostics” section and determined that: The ECM and/or MIL (Malfunction Indicator Lamp) are operating correctly. There are no DTC(s) stored.
  • Page 566 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING A scan tool can be used to help detect intermittent conditions. The scan tool has several features that can be used to locate an intermittent condition. The following features can be used in finding an intermittent fault: The “Record”...

  • Page 567: Hard Start Symptom

    FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Hard Start Symptom Step Action Value(s) Definition: Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies. Was the “On-Board Diagnostic” (OBD) Go to OBD Go to Step 2 System Check performed?
  • Page 568 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Hard Start Symptom (Continued) 1. Check for a ECT sensor shifted in value. 2. With engine completely cool, mea- sure the resistance of the ECT sen- sor. 3. Refer to the Engine Coolant Tem- perature Sensor Temperature -vs- Resistance value table on the facing page of DTC 14 in the “Trouble Code...
  • Page 569 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Hard Start Symptom (Continued) 1. Check for proper operation of the TP sensor. 2. Check or throttle linkage sticking, binding or worn causing TP sensor voltage to be higher than normal. 3. If a problem is found, repair as nec- Go to OBD essary.

  • Page 570: Surges And/Or Chuggles Symptom

    SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Surges and/or Chuggles Symptom Step Action Value(s) Definition: Engine power variation under steady throttle or cruise. Feels like the engine speeds up and slows down with no change in the throttle lever position. Was the “On-Board Diagnostic”...
  • Page 571 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Surges and/or Chuggles Symptom (Continued) 1. Check integrity of the primary and secondary wiring. 2. Check routing of the wiring. 3. Check condition of IC module, pick-up coil, distributor cap, rotor and spark plug wires. 4.

  • Page 572: Lack Of Power, Sluggish Or Spongy Symptom

    SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Surges and/or Chuggles Symptom (Continued) 1. Visually/physically check vacuum hoses for splits, kinks and proper connections and routing. 2. If a problem is found, repair as Go to OBD necessary. System Go to Step 16 Was a problem found? Check 1.
  • Page 573 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Lack of Power, Sluggish or Spongy Symptom (Continued) 1. Check for proper fuel pressure while the condition exists. Refer to Table A-4 in “General Sys- tem Diagnostics” section. 2. If a problem is found, repair as Go to OBD necessary.
  • Page 574 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Lack of Power, Sluggish or Spongy Symptom (Continued) 1. Check for intermittent opens or short to grounds in the ECT sensor, MAP sensor and TP sensor circuits. Also check or throttle linkage sticking, binding or worn.

  • Page 575: Detonation/Spark Knock Symptom

    FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Lack of Power, Sluggish or Spongy Symptom (Continued) 1. Check for excessive resistance on the bottom of the boat such as dirt, barnacles, etc. 2. Check for proper propeller size and pitch for that application. 3.
  • Page 576 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Detonation/Spark Knock Symptom (Continued) 1. Check for good ignition system ground. 2. Check spark plugs for proper gap and heat range. 3. If a problem is found, repair as Go to OBD necessary.
  • Page 577 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Detonation/Spark Knock Symptom (Continued) 1. Check for ECT sensor being shifted in value. 2. Check for proper output voltage of the TP sensor at closed throttle and wide open throttle. Also check throttle linkage for sticking, binding or worn.

  • Page 578: Hesitation, Sag, Stumble Symptom

    SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Hesitation, Sag, Stumble Symptom Step Action Value(s) Definition: Momentary lack of response as the throttle lever is advanced. Can occur at all engine speeds. Usually most severe when first starting out. May cause engine to stall if severe enough.
  • Page 579 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Hesitation, Sag, Stumble Symptom (Continued) 1. Remove spark plugs and check for wet plugs, cracks. wear, improper gap, burned electrodes or heavy deposits. Refer to Distributor Ignition System. NOTE: If park plugs are gas or oil fouled, the cause of the fouling must be deter- mined before replacing the spark plugs.

  • Page 580: Cuts Out, Misses Symptom

    SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Hesitation, Sag, Stumble Symptom (Continued) 1. Review all diagnostic procedures within this table. 2. If all procedures have been com- pleted and no malfunctions have been found, review/inspect the fol- lowing: Visual/physical inspection. Scan tool data.
  • Page 581 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Cuts Out, Misses Symptom (Continued) 1. Check fuel injectors. Refer to Injector Balance Test in “General System Diagnostics” sec- tion. 2. If a problem is found, repair as nec- Go to OBD essary.

  • Page 582: Rough, Unstable, Or Incorrect Idle, Stalling Symptom

    SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Cuts Out, Misses Symptom (Continued) 1. Check for Electromagnetic Interfer- ence (EMI). A missing condition can be caused by EMI on the reference circuit. EMI can usually be detected by monitoring engine rpm with a scan tool or tachometer.
  • Page 583 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Rough, Unstable, or Incorrect Idle, Stalling Symptom (Continued) 1. Check integrity of the primary and secondary wiring. 2. Check routing of the wiring. 3. Check condition of IC module, pick-up coil, distributor cap, rotor and spark plug wires.
  • Page 584 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Rough, Unstable, or Incorrect Idle, Stalling Symptom (Continued) 1. Check for fuel in pressure regulator vacuum hose. 2. If fuel is present, replace the fuel pressure regulator assembly. Refer to Fuel Metering System in “Description and System Operation”...
  • Page 585 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Rough, Unstable, or Incorrect Idle, Stalling Symptom (Continued) 1. Check following Engine Mechanical items: Check compression. Sticking or leaking valves. Worn camshaft lobe(s). Valve timing. Broken valve springs. 2. If a problem is found, repair as nec- Go to OBD essary.

  • Page 586: Poor Fuel Economy Symptom

    SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Poor Fuel Economy Symptom Step Action Value(s) Definition: Fuel economy is noticeably lower than expected. Also, economy is noticeably lower than it was on this engine at one time. Was the “On-Board Diagnostic” (OBD) Go to OBD Go to Step 2 System Check performed?
  • Page 587 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Poor Fuel Economy Symptom (Continued) 1. Visual (physically) check vacuum hoses for splits, kinks and improper connections and routing. 2. If a problem is found, repair as nec- Go to OBD essary. System Go to Step 9 Was a repair required?
  • Page 588 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Dieseling, Run-On Symptom Step Action Value(s) Definition: Engine continues to run after key is turned “OFF,” but runs very rough. If engine runs smooth, check ignition switch and adjustment. Was the “On-Board Diagnostic” (OBD) Go to OBD Go to Step 2 System Check performed?

  • Page 589: Backfire Symptom

    FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Dieseling, Run-On Symptom (Continued) 1. Review all diagnostic procedures within this table. 2. If all procedures have been com- pleted and no malfunctions have been found, review/inspect the fol- lowing: Visual physical inspection. Scan tool data.
  • Page 590 SERVICE MANUAL NUMBER 23 FUEL INJECTION SYSTEM TROUBLESHOOTING Backfire Symptom (Continued) 1. Check for proper operation of Igni- tion Control (IC) circuit and the Knock Sensor (KS) circuit. 2. If a problem is found, repair as nec- Go to OBD essary.
  • Page 591 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 Backfire Symptom (Continued) 1. Check for intermittent opens or short to grounds in the MAP sensor and TP sensor circuits. Also check for throttle linkage sticking, binding or worn. 2. An intermittent failure may not store a DTC.
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  • Page 593 FUEL INJECTION SYSTEM TROUBLESHOOTING SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5D-34 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 594 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 FUEL SYSTEM Section 5E - General System Diagnostics Table of Contents Diagnostic Circuit Check ... . . 5E-2 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Scan Tool Normal Specifications (Idle / Symptom Chart (J-2 Circuits) .

  • Page 595: Diagnostic Circuit Check

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Diagnostic Circuit Check The Diagnostic Circuit Check is an organized approach to identifying a problem created by an electronic engine control system malfunction. It must be the starting point for any drive- ability complaint diagnosis because it directs the service technician to the next logical step in diagnosing the complaint.

  • Page 596: Mefi 1 - Ecm Connector Chart For 454/502 Mag Mpi And 8.2L Mpi

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Scan Tool Normal Specifications (Idle / Warm Engine / Closed Throttle / Neutral) SCAN POSITION UNITS DISPLAYED TYPICAL DATA VALUE Memory Calibration Check Varies with Software revision Calibration and Check Sum in ECM Oil Press/IO Level (See Note) OK/LO Engine Overtemp...
  • Page 597 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 J-2 Output Connector (Rear) Shaded Area Denotes Pin Connector Location IMPORTANT: The following conditions must be met before testing. 1. Engine at operating temperature. 2. Ignition on or engine running. 3. Scan tool not connected. THESE NOTES APPLY TO FOLLOWING ECM CONNECTOR AND SYMPTOM CHARTS The “B+”...

  • Page 598: Diagnostic Trouble Codes

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Diagnostic Trouble Codes MEFI 1 - Codes for the 454 / 502 Mag MPI and 8.2L MPI Engines Code Number Code Description Code 14 (ECT) Engine Coolant Temperature Code 21 (TP) Throttle Position Sensor Code 23 (IAT) Intake Air Temperature Code 33...

  • Page 599: Engines

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - Codes for the 454 cid (7.4L) / 502 cid (8.2L) Engines Code Connection Conditions Comments Number Minimum run time (10 sec) Open circuit ECT high Sensor output high (cold) > 240 Faulty sensor counts Minimum run time (10 sec) sensor...

  • Page 600: Special Tools

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - Codes for the 454 cid (7.4L) / 502 cid (8.2L) Engines (continued) Code Connection Conditions Comments Number Open secondary Ignore first 20 spark events requires wire Coil driver fault 8 faults to set code Open primary cable Checksum error Reserved - Invalid ECM checksum Bad ECM...
  • Page 601 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Special Tools (continued) Diagnostic Code Tool 94008 Flashes light to display problem codes (Rinda Technolo- gies) Harness Test Adapt- Allows multi-meter connections with wiring J-35616 harness. Used to perform fuel system pressure 91-805918A2 Fuel Shut Off Tool tests Used with the fuel shut off tool to adapt to...
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  • Page 603 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Symptom Chart (J-1 Circuits) See page 5E-4 for NOTES Circuit Diagnostic Normal Voltage (CKT) (CKT) Wire Tro ble Trouble Possible Wire Possible Color Ignition Engine Function Number...

  • Page 604: Mefi 1 - 454/502 Mag Mpi And 8.2L Mpi Symptom Chart (J-1 Circuits)

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Symptom Chart (J-1 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Wire Wire Tro ble Trouble Possible Possible Color Ignition Engine Function Number Codes Symptoms Running DTC(s)
  • Page 605 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Symptom Chart (J-1 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Wire Wire Tro ble Trouble Possible Possible Ignition Engine Function Number Color Codes Symptoms Running DTC(s)

  • Page 606: Mefi 1 - 454/502 Mag Mpi And 8.2L Mpi Symptom Chart (J-2 Circuits)

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Symptom Chart (J-2 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Wire Wire Tro ble Trouble Possible Possible Color Ignition Engine Function Number Codes Symptoms Running DTC(s)
  • Page 607 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Symptom Chart (J-2 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Wire Wire Tro ble Trouble Possible Possible Color Ignition Engine Function Number Codes Symptoms Running DTC(s)
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  • Page 609 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Wiring System Diagram (1 of 4) J2-21 467 DK BLU 450 BLK/WHT J2-15 439 PNK/BLK J2-20 450 BLK/WHT 468 DK GRN J2-5 J2-7 901 WHT J2-22 901 WHT J2-9...
  • Page 610 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 To Injector Fuse Injectors 2,3,5,8 To Ignition Relay Injectors 1,4,6,7 Fuel Pump Fuse Fuel Pump Relay Fuel Pump To ECM/BAT Fuse Idle Air Control Motor Data Link Connector Injector Driver Injector Ground Fuel Injector Ground Injector Driver Port Fuel Jumper Port Fuel Jumper...
  • Page 611 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Wiring System Diagram (2 of 4) J1-24 472 TAN 813 BLK 813 BLK J1-10 417 DK BLU 416 GRY J1-15 813 BLK J1-13 813 BLK 813 BLK 416 GRY J1-31...
  • Page 612 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Intake Air Temperature Sensor Throttle Position Sensor Manifold Absolute Pressure Sensor Engine Coolant Temperature Sensor IAT Sensor TP Signal TP 5V Reference TP and IAT Ground MAP 5V Reference MAP Signal MAP Ground ECT Signal Index 90-861326--1 MARCH 1999...
  • Page 613 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Wiring System Diagram (3 of 4) J1-14 450 BLK/WHT J1-30 450 BLK/WHT A B C D J2-23 423 WHT J2-8 430 PUR/WHT J2-24 424 TAN/BLK J2-6 453 BLK/RED 121 BRN...
  • Page 614 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 IC Module To Drawing 4 Of 4 Harness Connector Ignition Coil ECM Ground ECM Ground Ignition Control Signal Ignition Control Reference High Ignition Control Bypass Ignition Control Reference Low Coolant Over Temperature Discrete Switch Discrete Switch Index 90-861326--1 MARCH 1999...
  • Page 615 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 1 - 454/502 Mag MPI and 8.2L MPI Wiring System Diagram (4 of 4) 150 BLK 3 PNK 902 RED 439 PNK/BLK 2 RED J1-11 30 86 85 87 J1-32 440 ORN 2 RED J1-16 440 ORN...

  • Page 616: Mefi 2 - Ecm Connector Chart For 7.4L Mpi

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - ECM Connector Chart For 7.4L MPI The following chart will aid in diagnosis of symptoms. These voltages were derived from a known good engine. The voltages shown were done with the electrical system intact and operational.
  • Page 617 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 THESE NOTES APPLY TO FOLLOWING ECM CONNECTOR AND SYMPTOM CHARTS. The “B+” Symbol indicates a system voltage (battery). NOTE: 1: Battery voltage for first two seconds, then 0 volts. NOTE: 2: Varies with temperature. NOTE: 3: Varies with manifold vacuum.
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  • Page 619: Mefi 2 - 7.4L Mpi Symptom Chart (J-1 Circuits)

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Symptom Chart (J-1 Circuits) Circuit Diagnostic Normal Voltage (CKT) (CKT) Wire Wire Tro ble Trouble Possible Possible Color Ignition Engine Function Number Codes Symptoms Running DTC(s) Poor Fuel Knock Economy, J1-1...
  • Page 620 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Symptom Chart (J-1 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Tro ble Trouble Wire Wire Possible Possible Number Color Ignition Engine Codes Function Symptoms Running DTC(s) Poor Perfor- mance, Surge, Poor 1.46V...
  • Page 621 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Symptom Chart (J-1 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Tro ble Trouble Wire Wire Possible Possible Number Color Ignition Engine Codes Function Symptoms Running DTC(s) J1-27 Not Used –...
  • Page 622 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Symptom Chart (J-1 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Tro ble Trouble Wire Wire Possible Possible Number Color Ignition Engine Codes Function Symptoms Running DTC(s) J2-12 Not Used –...
  • Page 623 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Symptom Chart (J-1 Circuits) (Continued) Circuit Diagnostic Normal Voltage (CKT) (CKT) Tro ble Trouble Wire Wire Possible Possible Number Color Ignition Engine Codes Function Symptoms Running DTC(s) Audio Warn- ing System Discrete Activated...
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  • Page 625 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Wiring System Diagram (1 of 4) J2-21 467 DK BLU 450 BLK/WHT J2-15 439 PNK/BLK J2-20 450 BLK/WHT 468 DK GRN J2-5 J2-7 901 WHT J2-22 901 WHT 465 DK GRN/WHT J2-9 450 BLK...
  • Page 626 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 To Injector Fuse To Ignition Relay Injectors 2,3,5,8 Injectors 1,4,6,7 Fuel Pump Fuse Fuel Pump Relay Fuel Pump To ECM/BAT Fuse Idle Air Control Motor Data Link Connector Injector Driver Injector Ground Fuel Injector Ground Injector Driver Port Fuel Jumper Port Fuel Jumper...
  • Page 627 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Wiring System Diagram (2 of 4) J1-24 472 TAN 813 BLK 813 BLK J1-10 417 DK BLU 416 GRY J1-15 813 BLK J1-13 813 BLK 813 BLK 416E GRY J1-31 432 LT GRN J1-9...
  • Page 628 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Intake Air Temperature Sensor Throttle Position Sensor Manifold Absolute Pressure Sensor Engine Coolant Temperature Sensor IAT Sensor TP Signal TP 5V Reference TP and IAT Ground MAP 5V Reference MAP Signal MAP Ground ECT Signal Index 90-861326--1 MARCH 1999...
  • Page 629 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Wiring System Diagram (3 of 4) J1-14 450 BLK/WHT J1-30 450 BLK/WHT A B C D J2-23 423 WHT J2-8 430 PUR/WHT J2-24 424 TAN/BLK J2-6 453 RED/BLK 121 BRN 3 PNK 902 RED...
  • Page 630 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 IC module Water Temp Sender For Gauge To Drawing 4 of 4 Harness Connector Ignition Coil Gear Lube Switch Oil Pressure Switch ECM Ground ECM Ground Ignition Control Signal Ignition Control Reference High Ignition Control Bypass Ignition Control Reference Low Coolant Over Temperature And Discrete Switch Output...
  • Page 631 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 2 - 7.4L MPI Wiring System Diagram (4 of 4) 150 BLK 3 PNK 902 RED 439 PNK/BLK 2 RED J1-11 30 86 85 J1-32 440 ORN 2B RED J1-16 440 ORN 440 ORN 439 PNK 485 GRN...
  • Page 632 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 To Key Switch 2-Pin Harness Connector Inj/ECM fuse 10A System/Ignition Relay ECM BAT Fuse 15A To Fuel Pump Relay To DLC Connector Knock Module Knock Sensor To Ignition Coil B+ To Injectors Ignition Fuse Battery Battery Knock Sensor Signal...

  • Page 633: Mefi 3 - Ecm Connector Chart

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - ECM Connector Chart The following chart will aid in diagnosis of symptoms. These voltages were derived from a known good engine. The voltages shown were done with the electrical system intact and operational.
  • Page 634 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - ECM J-1 and J-2 Circuit/Symptom Chart In the following J-1 and J-2 Circuit/Symptom Charts only those pins which are used by the ECM are shown. Pin numbers not listed are not used. The “B+”...
  • Page 635 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - J-1 Circuits (continued) Circuit Diag- Normal Voltage (CKT) nostic Wire Wire Possible Possible Num- Trouble Func- Color Symptoms Ignition Engine Codes tion Running DTC(s) Knock Sensor Poor Fuel Economy, Signal J1-14 –...
  • Page 636 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - J-2 Circuits Circuit Diag- Normal Voltage (CKT) nostic Wire Wire Possible Possible Num- Trouble Func- Color Symptoms Ignition Engine Codes tion Running DTC(s) J2-1 Battery None No Start TP and High Idle, Rough Idle, Poor Per- J2-3 21,23...
  • Page 637 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - J-2 Circuits (continued) Circuit Diag- Normal Voltage (CKT) nostic Wire Wire Possible Possible Num- Trouble Func- Color Symptoms Ignition Engine Codes tion Running DTC(s) Master/ Lack Of Data From Other En- J2-21 None Slave...
  • Page 638 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - ECM Wiring PAGE 1 of 4 INJECTORS 2, 3, 5, 8 From INJ/ J1-1 467 DK BLU FUSE 10 AMP 439 PNK INJECTORS 1, 4, 6, 7 468 DK GRN J1-17 From 439 PNK...
  • Page 639 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - ECM Wiring PAGE 2 of 4 INTAKE AIR TEMPERATURE J2-30 472 TAN INTAKE AIR (IAT) SENSOR SIGNAL TEMPERATURE (IAT) 813 BLK J2-3 SENSOR GROUND 813 BLK 813 BLK 417 DK BLU J2-26 (TP) 416 GRY...
  • Page 640 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - ECM Wiring PAGE 3 of 4 TO FUEL PUMP RELAY FUSE BATTERY 440 0RN J2-1 FEED 2 RED ECM BAT FUSE/ 440 0RN TO DLC DLC 15A CONNECTOR SYSTEM/IGNITION RELAY 2 RED IGN / INJ FUSE 902 RED...
  • Page 641 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 MEFI 3 - ECM Wiring PAGE 4 of 4 450 BLK J1-4 IC MODULE GROUND EST MODULE 450 BLK J1-5 GROUND 450 BLK J1-20 GROUND 423 WHT J1-10 IGNITION CONTROL DIST. REFERENCE 430 PUR/WHT J2-10 “HIGH”...
  • Page 642 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Injector Balance Test Test Procedure (Refer to the following figure for test set-up.) The injector balance tester is a tool used to turn the injector ON for a precise amount of time, thus spraying a measured amount of fuel into the manifold. This causes a drop in fuel rail pressure that we can record and compare between each injector.

  • Page 643: Test Example

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 NOTE: The entire test should not be repeated more than once without running the engine to prevent flooding. (This includes any retest on faulty injectors.) Test Example 300ms Injector 1st Reading (Initial Pressure) Fuel Pressure Gauge 2nd Reading (Pressure After Drop) EXAMPLE...

  • Page 644: General Diagnostic Tests

    GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 General Diagnostic Tests IMPORTANT: These tests are for MEFI 1 and MEFI 2 Engines only. MEFI 3 diagnostic tests will be provided as soon as available. References to 454 cid / 502 cid engines are MEFI 1, references to 7.4L engines are MEFI 2.
  • Page 645 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 CIRCUIT DESCRIPTION: The on-board diagnostic system check must be the starting point for any driveability com- plaint diagnosis. Before using this procedure, you should perform a careful visual/physical check of the ECM and engine grounds for being clean and tight. The on-board diagnostic system check is an organized approach to identifying a problem created by an electronic engine control system malfunction.
  • Page 646 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 On-Board Diagnostic (OBD) System Check (Non-Scan) Step Action Value(s) 1. Ignition “ON,” engine “OFF.” 2. install Marine Diagnostic Trouble Code (MDTC) tool and switch it to “Normal Mode.” 3. Observe the Malfunction Indica- tor Lamp (MIL).
  • Page 647 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 On-Board Diagnostic (OBD) System Check (Scan) 461 ORN/BLK 451 WHT/BLK ECM/DLC 15amp fuse DLC Connector Marine Diagnostic Code Tool ECM, Injector Knock Sensor Module 10amp Fuse (ORN-Some Models) (BLK-Some Models) Serial Data ECM Ground ECM Ground Diagnostic Test Terminal Malfunction Indicator Lamp (MIL)
  • Page 648 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 TEST DESCRIPTION: Number(s) below refer to the Step number(s) on the Diagnostic Table: 1. The MIL should be “ON” steady with the ignition “ON,” engine “OFF.” If not, chart A-1 should be used to isolate the malfunction. 2.
  • Page 649 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 On-Board Diagnostic (OBD) System Check (Scan) Step Action Value(s) 1. Ignition “ON,” engine “OFF.” 2. Install Marine Diagnostic Trouble Code (MDTC) tool and switch it to “Normal Mode.” 3. Observe the Malfunction Indica- tor Lamp (MIL).
  • Page 650 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-1 (1 of 4): No Malfunction Indicator Lamp (MIL) - Marine Diagnostic Trouble Code (MDTC) Tool Installed 461 ORN/BLK 451 WHT/BLK ECM/DLC 15amp fuse DLC Connector Marine Diagnostic Code Tool ECM, Injector Knock Sensor Module 10amp Fuse (ORN-Some Models) (BLK-Some Models) Serial Data...
  • Page 651 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-1 (2 of 4): No Malfunction Indicator Lamp (MIL) - (MDTC) Tool Installed DIAGNOSTIC AIDS: An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for the following items: Inspect the ECM harness and connectors for improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.
  • Page 652 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-1 (3 of 4): No Malfunction Indicator Lamp (MIL) -(MDTC) Tool Installed Action Value Step Was the “On-Board Diagnostic” (OBD) Go to OBD System Check Performed? Go to Step 2 System Check Attempt to start the engine.
  • Page 653 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-1 (4 of 4): No Malfunction Indicator Lamp (MIL) - Marine Diagnostic Trouble Code (MDTC) Tool Installed Step Action Value(s) Locate and repair open or short to Go to OBD System Check ground in CKT 440.
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  • Page 655 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-2 (1 of 3): Malfunction Indicator Lamp “On” Steady - No DLC Data or Will Not Flash DTC 12 - Marine Diagnostic Trouble Code (MDTC) Tool Installed 461 ORN/BLK 451 WHT/BLK ECM/DLC 15amp fuse DLC Connector Marine Diagnostic Code Tool ECM, Injector Knock Sensor Module 10amp Fuse...
  • Page 656 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-2 (2 of 3): Malfunction Indicator Lamp “On” Steady - No DLC Data or Will Not Flash DTC 12 - Marine Diagnostic Trouble Code (MDTC) Tool Installed DIAGNOSTIC AIDS: An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation.
  • Page 657 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-2 (3 of 3): Malfunction Indicator Lamp “On” Steady - No DLC Data or Will Not Flash DTC 12 - Marine Diagnostic Trouble Code (MDTC) Tool Installed Step Action Value(s) Was the “On-Board Diagnostic” (OBD) Go to OBD System Check Performed?
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  • Page 659 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-3 (1 of 5): Engine Cranks But Will Not Run 121 BRN 3 PNK To Term “87” Of System Relay Injector/ECM/KS module fuse 10a Injectors Engine Ground Ignition Feed Injector Driver Ignition Control Dist.
  • Page 660 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-3 (2 of 5): Engine Cranks But Will Not Run DIAGNOSTIC AIDS: This chart assumes that battery voltage and engine cranking speed are OK, and there is adequate fuel in the tank. Water or foreign material in fuel system can cause a no start.
  • Page 661 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-3 (3 of 5): Engine Cranks But Will Not Run Step Action Value(s) 1. Disconnect one injector electri- cal connector. 2. Connect test light J34730-2C to injector harness connector. 3. While cranking engine, check for blinking light.
  • Page 662 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-3 (4 of 5): Engine Cranks But Will Not Run 1. Disconnect injector that did not blink. 2. Ignition “ON”. 3. Using a test light connected to – ground,probe injector harness connector terminals. Does Test Light...
  • Page 663 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-3 (5 of 5): Engine Cranks But Will Not Run Step Action Value(s) Locate and repair open in CKT 467 Go to OBD System Check or CKT 468. – – Is Action Complete? Check for short to ground in CKT Go to OBD System Check...
  • Page 664 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5E-71 Downloaded from https://needmanual.com/...
  • Page 665 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-4 (1 of 5): Fuel System Diagnosis FUEL SHUT-OFF TOOL 75752 CIRCUIT DESCRIPTION: When the ignition is turned “ON,” the Engine Control Module (ECM) will turn the fuel pump “ON” for 2 seconds. During engine cranking, the ECM will turn “ON” the fuel pump. It will remain “ON”...
  • Page 666 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-4 (2 of 5): Fuel System Diagnosis TEST DESCRIPTION: Wrap a shop towel around the fuel pressure connector to absorb any small amount of fuel leakage that may occur when installing the gauge. Ignition “ON,” pump pressure should be 34-38 psi (234-262 kPa).
  • Page 667 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-4 (3 of 5): Fuel System Diagnosis Step Action Value(s) “On-Board Diagnostic” (OBD) System – Go to OBD Go to Step 2 Check performed? System Check Install fuel pressure gauge. Ignition “OFF” for 10 seconds.
  • Page 668 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-4 (4 of 5): Fuel System DiagnosisContinued) Ignition “OFF” for 10 seconds. Ignition “ON.” Block fuel pressure line between the fuel pump and fuel rail us- ing fuel shut-off valve tool. Does fuel pressure hold?
  • Page 669 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-4 (5 of 5): Fuel System Diagnosis (Continued) Ignition “OFF”. Disconnect fuel return line. Following manufac- tures recommenda- tions, connect a hose to pressure regulator side of return line. 34-38 psi Insert the other end (234-262) kPa into an approved gas- oline container.
  • Page 670 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5E-77 Downloaded from https://needmanual.com/...
  • Page 671 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-5 (1 of 3): Fuel System Electrical Test 902 RED 339 PNK/BLK 465 DK GRN/WHT J2-9 450 BLK/WHT 450 BLK/WHT 120 GRY 150 BLK To System Relay Fuel Pump Relay Fuse 15a Fuel Pump Relay Fuel Pump Fuel Pump Relay Driver...
  • Page 672 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-5 (2 of 3): Fuel System Electrical Test Step Action Value(s) Was The “On-Board Diagnostic” (OBD) System Check – Go to OBD Go to Step 2 Performed? System Check 1. Ignition “OFF”. 2.
  • Page 673 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-5 (3 of 3): Fuel System Electrical Test Step Action Value(s) 1. Check for plugged fuel filter, vapor lock condition, restricted fuel lines, discon- nected hoses, and proper – fuel level. 2. If a problem is found, repair Go to OBD as necessary.
  • Page 674 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5E-81 Downloaded from https://needmanual.com/...
  • Page 675 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-6 (1 of 2): EFI System/Ignition Relay Check 902 RED From 5-pin Connector 50a Circuit Breaker 90 Amp Fuse Battery System Relay To ECM Term “J1-11” Injector/Ks Module Fuse 10a To Fuel Pump Relay Fuse 15a To Ignition Coil Term “8”...
  • Page 676 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-6 (2 of 2): EFI System/Ignition Relay Check Step Action Value(s) Was The “On-Board Diagnostic” (OBD) System Check – Go to OBD Go to Step 2 Performed? System Check 1. Ignition “OFF.” 2.
  • Page 677 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-7 (1 of 6): Ignition System Check “C” “+” BLK CONNECTOR GRY CONNECTOR TACH 902 RED 3 PNK 121 GRY 121 WHT GRY CONNECTOR Ignition Coil Connector Distributor To System Relay Ignition Coil Distributor Tach Wire Ignition Control Module...
  • Page 678 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-7 (2 of 6): Ignition System Check DIAGNOSTIC AIDS: An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for the following items: Poor connection or damaged harness.
  • Page 679 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-7 (3 of 6): Ignition System Check (Continued) Step Action Value(s) Was the “On-Board Diagnostic” (OBD) System Check Go to OBD Go to Step 2 Performed? System Check 1. Check spark plug wires for open circuits, cracks...
  • Page 680 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-7 (4 of 6): Ignition System Check (Continued) Step Action Value(s) 1. Disconnect distributor 4-wire connector. 2. Check for secondary spark. Go to Step 18 Go to Step 5 Is Adequate Spark Present? 1.
  • Page 681 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-7 (5 of 6): Ignition System Check (Continued) Step Action Value(s) 1. Disconnect distributor 4-wire connector. 2. Remove distributor cap. 3. Disconnect pick-up coil con- nector from the distributor ignition control module. 4.
  • Page 682 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-7 (6 of 6): Ignition System Check Step Action Value(s) Replace faulty pick-up coil. Go to OBD – System – Is Action Complete? Check Inspect distributor cap for water, cracks, etc. If OK, replace faulty Go to OBD –...
  • Page 683 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-8 (1 of 2): Idle Air Control (IAC) Functional Test 441 LT BLU/WHT 442 LT BLU/BLK 443 LT GRN/WHT 444 LT GRN/BLK Idle air control (IAC) valve IAC Coil “a” High IAC Coil “a” Low IAC Coil “b”...
  • Page 684 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Chart A-8 (2 of 2): Idle Air Control (IAC) Functional Test Step Action Value(s) Was the “On-Board Diagnostic” (OBD) System Check – Go to OBD Go to Step 2 performed? System Check 1. Engine should be at normal operating temperature.
  • Page 685 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan - 454 / 502 Mag MPI and 8.2L MPI Only (1 of 5) TAN/ 121 TAN 3 PNK PUR C BLU/ J1-6 To Buzzer To Ignition To Audio Warning Switches To Tach To System Relay Term “87”...
  • Page 686 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 454 / 502 Mag MPI and 8.2L MPI Only (2 of 5) NOTE: The ECM should only be replaced after all switches and circuits have been tested and found to be functioning properly.
  • Page 687 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 454 / 502 Mag MPI and 8.2L MPI Only (3 of 5) TESTING GEAR LUBE MONITOR SWITCH STEP ACTION VALUE PROCEED TO 1. Disconnect BLU/TAN wire from gear lube monitor.
  • Page 688 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 454 / 502 Mag MPI and 8.2L MPI Only (4 of 5) TESTING CIRCUITS FOR SHORT-TO-GROUND (–) STEP ACTION VALUE PROCEED TO 1. Disconnect BLU/TAN wire from oil pres- sure switch.
  • Page 689 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 454 / 502 Mag MPI and 8.2L MP Only (5 of 5) TESTING FOR OPEN CIRCUITS STEP ACTION VALUE PROCEED TO 1. Disconnect PUR wire from oil pressure switch.
  • Page 690 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5E-97 Downloaded from https://needmanual.com/...
  • Page 691 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan - 7.4L MPI Only (1 of 5) 3 PNK DK BLU 112 GRY J2-11 31A DK GRN 31 TAN J2-26 3 PNK J1-4 931 BRN 585 TAN/WHT J1-6 121 WHT Harness Connector...
  • Page 692 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 7.4L MPI Only (2 of 5) NOTE: The ECM should only be replaced after all switches and circuits have been tested and found to be functioning properly. TESTING BUZZER STEP ACTION...
  • Page 693 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 7.4L MPI Only (3 of 5) TESTING GEAR LUBE MONITOR SWITCH STEP ACTION VALUE PROCEED TO 1. Disconnect TAN/WHT wire from gear lube monitor. 2. Empty gear lube from monitor. 3.
  • Page 694 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 7.4L MPI Only (4 of 5) TESTING CIRCUITS FOR SHORT-TO-GROUND (–) STEP ACTION VALUE PROCEED TO 1. Disconnect PUR wire from oil pressure switch. 2. Disconnect TAN/WHT wire from gear lube monitor.
  • Page 695 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 Discrete Input Circuit Check - Non-Scan 7.4L MPI Only (5 of 5) TESTING FOR OPEN CIRCUITS STEP ACTION VALUE PROCEED TO 1. Disconnect PUR wire from oil pressure switch. 2. Disconnect TAN/WHT wire from gear lube monitor.
  • Page 696 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5E-103 Downloaded from https://needmanual.com/...
  • Page 697 GENERAL SYSTEM DIAGNOSTICS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5E-104 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 698 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 FUEL SYSTEM Section 5F - Trouble Code Diagnostics- 454 / 502 MAG MPI & 8.2L MPI Table Of Contents Clearing Trouble Codes ....5F-3 Diagnostic Testing Using A Scan Tool 5F-21...
  • Page 699 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 IMPORTANT: These procedures apply to the MEFI 1 Product only. MEFI 3 Procedures will appear at the end of the section when available. Index Page 5F-2 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 700 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Clearing Trouble Codes Clearing Codes Using Diagnostic Code Tool (Non-Scan) NOTE: When clearing codes without the use of a scan tool, the battery must be fully charged.
  • Page 701 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Diagnostic Testing Without A Scan Tool (Non-Scan) Code 14 (1 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) Engine Coolant Temperature (ECT) Sensor To Map Sensor Engine Coolant Temperature (ECT) Sensor Ground CIRCUIT DESCRIPTION:...
  • Page 702 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 14 (2 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. This step checks if there is a problem with the ECM and wiring or if the problem is the coolant sensor.
  • Page 703 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 14 (3 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) STEP ACTION VALUE PROCEED TO CKT 410 open, faulty connection at ECM, or – –...
  • Page 704 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 21 (1 of 2): Throttle Position (TP) Sensor Circuit (Non-Scan) Throttle Position Sensor Front View Of Connector To IAT Sensor To Map Sensor Sensor Ground TP Signal 5V Reference Wide Open Throttle...
  • Page 705 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 21 (2 of 2): Throttle Position (TP) Sensor Circuit (Non-Scan) STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed? Check...
  • Page 706 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 23 (1 of 2): Intake Air Temperature (IAT) Sensor Circuit (Non-Scan) Intake Air Temperature Sensor To TP Sensor IAT Sensor Signal Sensor Ground CIRCUIT DESCRIPTION: The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the Electronic Control Module (ECM).
  • Page 707 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 23 (2 of 2): Intake Air Temperature (IAT) Sensor Circuit (Non-Scan) STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed?
  • Page 708 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 33 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) 814 BLK Manifold Absolute Pressure (Vacuum) To ECT Sensor To TP Sensor Map Signal Map And ECT Ground CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure...
  • Page 709 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. This step will determine if there is an adequate vacuum supply to the MAP sensor. If the gauge reading is erratic, refer to “Stalling, Rough, Unstable or Incorrect Idle”...
  • Page 710 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 33 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) STEP ACTION VALUE PROCEED TO Is voltage reading over 4 volts? – Step 5 Step 8 1.
  • Page 711 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 42 (1 of 3): Ignition Control (IC) Circuit (Non-Scan) “C” “+” 902 RED 3 PNK 121 GRY 121 WHT Ignition Coil Connector Distributor To System Relay Ignition Coil Distributor In-Line Harness (Tach)
  • Page 712 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 42 (2 of 3): Ignition Control (IC) Circuit (Non-Scan) DIAGNOSTIC AIDS: An intermittent problem may be caused by a poor or corroded connection, rubbed through wire connection, a wire that is broken inside the insulation, or a corroded wire.
  • Page 713 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 42 (3 of 3): Ignition Control (IC) Circuit (Non-Scan) (Continued) 1. Ignition OFF. 2 Di t ECM J1 d J2 2. Disconnect ECM J1 and J2 connectors. 3 Ignition ON 3.
  • Page 714 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 43 (1 of 3): Knock Sensor (Ks) Circuit (Non-Scan) FUSE 15A 485 GRN Knock Sensor Module To System Relay Starboard Knock Sensor Port Knock Sensor Knock Sensor Signal CIRCUIT DESCRIPTION: The ability to sense engine knock or detonation is accomplished with a module that sends...
  • Page 715 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 43 (2 of 3): Knock Sensor (KS) Circuit (Non-Scan) Step 5. This step confirms the ability of the KS module to remove the voltage from the signal line when it sees spark knock.
  • Page 716 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 43 (3 of 3): Knock Sensor (KS) Circuit (Non-Scan) STEP ACTION VALUE PROCEED TO 1. Disconnect knock module harness con- nector. 2. Connect a test light to battery positive (B+).
  • Page 717 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 51 (1 of 1): Calibration Memory Failure (Non-Scan) 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM.
  • Page 718 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Diagnostic Testing Using A Scan Tool (Scan) Code 14 (1 of 2): Engine Coolant Temperature (ECT) Sensor Circuit (Scan) Engine Coolant Temperature (ECT) Sensor To Map Sensor Engine Coolant Temperature (ECT) Sensor Ground CIRCUIT DESCRIPTION:...
  • Page 719 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 14 (2 of 2): Engine Coolant Temperature (ECT) Sensor Circuit (Scan) Number(s) below refer to step number(s) on the diagnostic table. Step 2. Code 14 will set if: Signal voltage indicates a coolant temperature above 266 F (130 C).
  • Page 720 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 21 (1 of 3): Throttle Position (TP) Sensor Circuit (Scan) Throttle Position Sensor Front View Of Connector To IAT Sensor To Map Sensor Sensor Ground TP Signal 5V Reference Wide Open Throttle...
  • Page 721 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 21 (2 of 3): Throttle Position (TP) Sensor Circuit (Scan) TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2: With throttle closed the TP sensor should read between .3 and .8 volt. If it does not, check throttle cable adjustment or for bent linkage.
  • Page 722 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 21 (3 of 3): Throttle Position (TP) Sensor Circuit (Scan) Connect DVOM between throttle position sen- sor terminals “B” and “A.” Voltage should be greater than 4 volts, is –...
  • Page 723 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 23 (1 of 2): Intake Air Temperature (IAT) Sensor Circuit (Scan) Intake Air Temperature Sensor To TP Sensor IAT Sensor Signal Sensor Ground CIRCUIT DESCRIPTION: The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the Electronic Control Module (ECM).
  • Page 724 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 23 (2 of 2): Intake Air Temperature (IAT) Sensor Circuit (Scan) TEST DESCRIPTION: Number(s) below refer to circled number(s) on the diagnostic chart. Step 2. A Code 23 will set, due to an open sensor, wire or connection. This test will determine if the wiring and ECM are OK.
  • Page 725 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 33 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) 814 BLK Manifold Absolute Pressure (Vacuum) To ECT Sensor To TP sensor Map Signal Map And ECT Ground CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure...
  • Page 726 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 4. Engine misfire or a low, unstable idle may set Code 33. Disconnect MAP sensor and system will go into backup mode.
  • Page 727 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 33 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) STEP ACTION VALUE PROCEED TO 1. Ignition OFF. 2. Connect DVOM between MAP sensor harness terminal “A”...
  • Page 728 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 42 (1 of 3): Ignition Control (IC) Circuit (Scan) “C” “+” 902 RED 3 PNK 121 GRY 121 WHT Ignition Coil Connector Distributor To System Relay Ignition Coil Distributor In-Line Harness (Tach)
  • Page 729 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 42 (2 of 3): Ignition Control (IC) Circuit (Scan) DIAGNOSTIC AIDS: Refer to “Intermittents” in “Troubleshooting.” An intermittent problem may be caused by a poor or corroded connection, rubbed through wire connection, a wire that is broken inside the insulation, or a corroded wire.
  • Page 730 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 42 (3 of 3): Ignition Control (IC) Circuit (Scan) 1. Ignition OFF. 2. Disconnect ECM connectors. 3. Ignition ON. 4. Use a DVOM with selector in the OHMS range.
  • Page 731 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 43 (1 of 3): Knock Sensor (KS) Circuit (Scan) FUSE 15A 485 GRN Knock Sensor Module To System Relay Starboard Knock Sensor Port Knock Sensor Knock Sensor Signal CIRCUIT DESCRIPTION: Sensing engine detonation or spark knock is accomplished with a module that sends a volt-...
  • Page 732 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 43 (2 of 3): Knock Sensor (KS) Circuit (Scan) STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed? Check...
  • Page 733 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 43 (3 of 3): Knock Sensor (KS) Circuit (Scan) STEP ACTION VALUE PROCEED TO 1. Connect a test light to ground. 2. Disconnect KS module harness connector. 3.
  • Page 734 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 Code 51 (1 of 2): Calibration Memory Failure (Scan) 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM.
  • Page 735 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5F-38 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 736 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5F-39 Downloaded from https://needmanual.com/...
  • Page 737 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5F-40 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 738 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5F-41 Downloaded from https://needmanual.com/...
  • Page 739 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5F-42 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 740 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5F-43 Downloaded from https://needmanual.com/...
  • Page 741 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5F-44 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 742 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5F-45 Downloaded from https://needmanual.com/...
  • Page 743 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5F-46 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 744 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5F-47 Downloaded from https://needmanual.com/...
  • Page 745 TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 5F-48 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 746 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 FUEL SYSTEM Section 5G - Trouble Code Diagnostics - 7.4L MPI Table Of Contents Clearing Trouble Codes ....5G-3 Diagnostic Testing Using A Scan Tool 5G-38...
  • Page 747 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 IMPORTANT: These procedures apply to the MEFI 1 Product only. MEFI 3 Procedures will appear at the end of the section when available. Index Page 5G-2 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...

  • Page 748: Clearing Trouble Codes

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Clearing Trouble Codes Clearing Codes Using Diagnostic Code Tool (Non-Scan) NOTE: When clearing codes without the use of a scan tool, the battery must be fully charged. The ability to clear codes is directly dependent on the battery being fully charged and able to start the engine with adequate cranking RPM.

  • Page 749: Diagnostic Testing Without A Scan Tool

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Diagnostic Testing Without A Scan Tool (Non-Scan) Code 14 (1 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) Low Temperature Indicated Engine Coolant Temperature (ECT) Sensor To Map Sensor Engine Coolant Temperature (ECT) Sensor Ground CIRCUIT DESCRIPTION:...
  • Page 750 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 14 (2 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) Low Temperature Indicated TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. This step checks if there is a problem with the ECM and wiring or if the problem is the ECT sensor.
  • Page 751 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 14 (3 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) Low Temperature Indicated ENGINE COOLANT TEMPERATURE SENSOR CHART ECT Sensor Temperature - to - Resistance Values (Approximate) OHMS 1,800 3,400 7,500...
  • Page 752 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 15 (2 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) High Temperature Indicated DIAGNOSTIC AIDS: Check for the following conditions: Poor connection at ECM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor ter- minal to wire connection.
  • Page 753 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 15 (3 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Non-Scan) High Temperature Indicated STEP ACTION VALUE PROCEED TO Locate and repair intermittent faulty connec- – – tions. If OK, replace faulty ECT sensor. Locate and repair short to ground in CKT 410.
  • Page 754 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 21 (1 of 2): Throttle Position (TP) Sensor Circuit (Non-Scan) Signal Voltage High Throttle Position Sensor Front View Of Connector To IAT Sensor To Map Sensor Sensor Ground TP Signal 5V Reference Wide Open Throttle Idle...
  • Page 755 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 21 (1 of 2): Throttle Position (TP) Sensor Circuit (Non-Scan) Signal Voltage High STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed? Check...

  • Page 756: Voltage Low

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 22 (1 of 2): Throttle Position (TP) Sensor Circuit (Non-Scan) Signal Voltage Low Throttle Position Sensor Front View Of Connector To IAT Sensor To Map Sensor Sensor Ground TP Signal 5V Reference Wide Open Throttle Idle...
  • Page 757 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 22 (2 of 2): Throttle Position (TP) Sensor Circuit (Non-Scan) Signal Voltage Low STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed? Check...
  • Page 758 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 5G-13 Downloaded from https://needmanual.com/...

  • Page 759: Temperature Indicated

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 23 (1 of 3): Intake Air Temperature (IAT) Sensor Circuit (Non-Scan) Low Temperature Indicated Intake Air Temperature Sensor To TP Sensor IAT Sensor Signal Sensor Ground CIRCUIT DESCRIPTION: The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the ECM.
  • Page 760 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 23 (2 of 3): Intake Air Temperature (IAT) Sensor Circuit (Non-Scan) Low Temperature Indicated TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. STEP 4. Check the harness terminals thoroughly for loose connections. If the resistance of the IAT sensor is monitored, the resistance should steadily decrease as the intake air warms up.
  • Page 761 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 23 (2 of 3): Intake Air Temperature (IAT) Sensor Circuit (Non-Scan) Low Temperature Indicated INTAKE AIR TEMPERATURE SENSOR CHART IAT Sensor Temperature - to - Resistance Values (Approximate) OHMS 1,800 3,400 7,500...
  • Page 762 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 25 (2 of 3): Intake Air Temperature (IAT) Sensor Circuit (Non-Scan) High Temperature Indicated DIAGNOSTIC AIDS: Check for the following conditions: Poor connection at ECM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor ter- minal to wire connection.
  • Page 763 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 25 (3 of 3): Intake Air Temperature (IAT) Sensor Circuit (Non-Scan) High Temperature Indicated STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed? Check...
  • Page 764 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 33 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) High Signal Voltage 814 BLK Manifold Absolute Pressure (Vacuum) To ECT Sensor To TP Sensor Map Signal Map And ECT Ground CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum).
  • Page 765 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) High Signal Voltage TEST DESCRIPTION: STEP 2. This step will determine if there is an adequate vacuum supply to the MAP sen- sor.
  • Page 766 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) High Signal Voltage (Continued) Repair low or unsteady vacuum problem. Is Verify – – action complete? Repair Check for plugged or leaking sensor vacuum Verify –...
  • Page 767 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 34 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) Low Signal Voltage 814 BLK Manifold Absolute Pressure (Vacuum) To ECT Sensor To TP Sensor Map Signal Map And ECT Ground CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum).
  • Page 768 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 34 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) Low Signal Voltage If the idle is rough or unstable, refer to “Troubleshooting” section for items which may cause an unstable idle.
  • Page 769 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 34 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Non-Scan) Low Signal Voltage STEP ACTION VALUE PROCEED TO Locate and repair intermittent faulty connec- – – tions. If OK, replace faulty MAP sensor. Is action complete? Locate and repair open or short to ground in –...

  • Page 770: Code 41 (1 Of 3): Ignition Control (Ic)

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 41 (1 of 3): Ignition Control (IC) Circuit (Non-Scan) - Open IC Circuit “C” “+” 902 RED 3 PNK 121 GRY 121 WHT Ignition Coil Connector Distributor To System Relay Ignition Coil Distributor In-Line Harness (Tach)
  • Page 771 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 DIAGNOSTIC AIDS: Check for the following conditions; Poor connections at ECM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connections. Damaged harness.
  • Page 772 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 41 (3 of 3): Ignition Control (IC) Circuit (Non-Scan) - Open IC Circuit STEP ACTION VALUE PROCEED TO 1. Reconnect ECM. 2. Start engine and idle for 2 minutes or un- til Marine Diagnostic Code Tool indicates a trouble code.

  • Page 773: Open Bypass Circuit, Or Grounded

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 42 (1 of 3): Ignition Control (IC) Circuit (Non-Scan) - Grounded IC Circuit, Open Bypass Circuit, or Grounded Bypass Circuit “C” “+” 902 RED 3 PNK 121 GRY 121 WHT Ignition coil connector Distributor To system relay...
  • Page 774 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 42 (2 of 3): Ignition Control (IC) Circuit (Non-Scan) - Grounded IC Circuit, Open Bypass Circuit, or Grounded Bypass Circuit DIAGNOSTIC AIDS: Check for the following conditions; Poor connections at ECM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connections.
  • Page 775 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 42 (3 of 3): Ignition Control (IC) Circuit (Non-Scan) - Grounded IC Circuit, Open Bypass Circuit, or Grounded Bypass Circuit STEP ACTION VALUE PROCEED TO 1. Ignition “OFF.” 2. Disconnect ECM harness connectors. 3000 to 6000 3.
  • Page 776 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 43 (1 of 2): Knock Sensor (KS) Circuit (Non-Scan) Continuous Knock Detected FUSE 15A 485 GRN Knock Sensor Module To System Relay Starboard Knock Sensor Port Knock Sensor Knock Sensor Signal CIRCUIT DESCRIPTION: Knock Sensor (KS) system circuit is accomplished with a module that sends a voltage signal to the ECM.
  • Page 777 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 43 (1 of 2): Knock Sensor (KS) Circuit (Non-Scan) Continuous Knock Detected STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed? Check 1.

  • Page 778: Code 44 (1 Of 3): Knock Sensor (Ks)

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 44 (1 of 3): Knock Sensor (KS) Circuit (Non-Scan) - No Knock Detected FUSE 15A 485 GRN Knock Sensor Module To System Relay Starboard Knock Sensor Port Knock Sensor Knock Sensor Signal CIRCUIT DESCRIPTION: Knock Sensor (KS) system circuit is accomplished with a module that sends a voltage signal...
  • Page 779 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 44 (2 of 3): Knock Sensor (KS) Circuit (Non-Scan) - No Knock Detected TEST DESCRIPTION: (CONTINUED) Step 5. This step checks the ground circuit from the KS module. If the test light is dim, check ground CKT 486 for excessive resistance.
  • Page 780 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 44 (3 of 3): Knock Sensor (KS) Circuit (Non-Scan) - No Knock Detected STEP ACTION VALUE PROCEED TO 1. Disconnect KS module 5-wire harness connector. 2. Using a test light connected to battery positive (B+), probe KS module harness termi- nal “D”...

  • Page 781: Code 51 (1 Of 2): Calibration Memory Failure (Non-Scan)

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 51 (1 of 2): Calibration Memory Failure (Non-Scan) 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM. This test is also used as a security measure to prevent improper use of calibrations or changes to these calibrations that may alter the designed function of the EFI system.
  • Page 782 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 52 (1 of 2): EEPROM Failure (Non-Scan) 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM. This test is also used as a security measure to prevent improper use of calibrations or changes to these calibrations that may alter the designed function of the EFI system.

  • Page 783: Diagnostic Testing Using A Scan Tool

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Diagnostic Testing Using A Scan Tool (Scan) Code 14 (1 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Scan) - Low Temperature Indicated Engine Coolant Temperature (ECT) Sensor To Map Sensor Engine Coolant Temperature (ECT) Sensor Ground CIRCUIT DESCRIPTION:...
  • Page 784 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 14 (2 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Scan) - Low Temperature Indicated TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. DTC 14 will set if signal voltage indicates a coolant temperature below -22 F (-30 C).

  • Page 785: Code 15 (1 Of 3): Engine Coolant

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 14 (3 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Scan) - Low Temperature Indicated ENGINE COOLANT TEMPERATURE SENSOR CHART ECT Sensor Temperature - to - Resistance Values (Approximate) OHMS 1,800 3,400...
  • Page 786 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 15 (2 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Scan) High Temperature Indicated DIAGNOSTIC AIDS: Check for the following conditions: Poor connection at ECM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor ter- minal to wire connection.
  • Page 787 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 15 (3 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Scan) High Temperature Indicated STEP ACTION VALUE PROCEED TO Trouble code 15 is intermittent. Locate and re- – – pair intermittent faulty connections.

  • Page 788: Code 21 (1 Of 2): Throttle Position (Tp) Sensor Circuit (Scan) High Signal Voltage

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 21 (1 of 2): Throttle Position (TP) Sensor Circuit (Scan) High Signal Voltage Throttle Position Sensor Front View Of Connector To IAT Sensor To Map Sensor Sensor Ground TP Signal 5V Reference Wide Open Throttle Idle...
  • Page 789 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 21 (2 of 2): Throttle Position (TP) Sensor Circuit (Scan) High Signal Voltage TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. With the throttle closed, the TP sensor voltage should read 0.3-0.9 volt. If it does not, check the throttle cable adjustment or for bent or binding linkage.
  • Page 790 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 22 (1 of 3): Throttle Position (TP) Sensor Circuit (Scan) Low Signal Voltage Throttle Position Sensor Front View Of Connector To IAT Sensor To Map Sensor Sensor Ground TP Signal 5V Reference Wide Open Throttle Idle...
  • Page 791 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 22 (2 of 3): Throttle Position (TP) Sensor Circuit (Scan) Low Signal Voltage TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. With the throttle closed, the TP sensor voltage should read 0.3-0.9 volt. If it does not, check the throttle cable adjustment or for bent or binding linkage.

  • Page 792: Temperature Indicated

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 22 (3 of 3): Throttle Position (TP) Sensor Circuit (Scan) Low Signal Voltage STEP ACTION VALUE PROCEED TO Locate and repair open or short to ground in CKT 416. Also check CKT 416E to the MAP –...
  • Page 793 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 23 (2 of 3): Intake Air Temperature (IAT) Sensor Circuit (Scan) - Low Temperature Indicated DIAGNOSTIC AIDS: Check for the following conditions: Poor connection at ECM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor ter- minal to wire connection.
  • Page 794 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 23 (2 of 3): Intake Air Temperature (IAT) Sensor Circuit (Scan) - Low Temperature Indicated STEP ACTION VALUE PROCEED TO Trouble code 23 is intermittent. Locate and re- – –...
  • Page 795 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 25 (1 of 2): Intake Air Temperature (IAT) Sensor Circuit (Scan) High Temperature Indicated Intake Air Temperature Sensor To TP Sensor IAT Sensor Signal Sensor Ground CIRCUIT DESCRIPTION: The Intake Air Temperature (IAT) Sensor uses a thermistor to control the signal voltage to the ECM.
  • Page 796 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 25 (2 of 2): Engine Coolant Temperature (IAT) Sensor Circuit (Scan) High Temperature Indicated TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. DTC 25 will set if signal voltage indicates a coolant temperature above 266 F (130 C).

  • Page 797: High Signal Voltage

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 33 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) High Signal Voltage 814 BLK Manifold Absolute Pressure (Vacuum) To ECT Sensor To TP sensor Map Signal Map And ECT Ground CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum).
  • Page 798 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) High Signal Voltage TEST DESCRIPTION: Number(s) below refer to step number(s) on the diagnostic table. Step 2. This step will determine if there is an adequate vacuum supply to the MAP sensor.
  • Page 799 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) High Signal Voltage STEP ACTION VALUE PROCEED TO Repair low or unsteady vacuum problem. Is – – action complete? Trouble code is intermittent.

  • Page 800: Low Signal Voltage

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 34 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) - Low Signal Voltage 814 BLK Manifold Absolute Pressure (Vacuum) To ECT Sensor To TP Sensor Map Signal Map And ECT Ground CIRCUIT DESCRIPTION: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure...
  • Page 801 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 34 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) - Low Signal Voltage TEST DESCRIPTION: Step 2. This step will determine if there is an adequate vacuum supply to the MAP sensor.
  • Page 802 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 34 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Scan) - Low Signal Voltage STEP ACTION VALUE PROCEED TO Repair low or unsteady vacuum problem. Is – – action complete? Trouble code is intermittent.
  • Page 803 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 41 (1 of 3): Ignition Control (IC) Circuit (Scan) - Open IC Circuit “C” “+” 902 RED 3 PNK 121 GRY 121 WHT Ignition coil connector Distributor To system relay Ignition coil Distributor In-line harness (tach)
  • Page 804 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 41 (2 of 3): Ignition Control (IC) Circuit (Scan) Open IC Circuit DIAGNOSTIC AIDS: Check for the following conditions: Poor connection at ECM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor ter- minal to wire connection.

  • Page 805: Open Bypass Circuit, Or Grounded

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 41 (2 of 3): Ignition Control (IC) Circuit (Scan) Open IC Circuit STEP ACTION VALUE PROCEED TO Locate and repair open in CKT 423. If a prob- – Step 6 lem is found, repair as necessary.
  • Page 806 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 42 (2 of 3): Ignition Control (IC) Circuit (Scan) Grounded IC Circuit, Open Bypass Circuit, or Grounded Bypass Circuit TEST DESCRIPTION: Step 2. DTC 42 means the ECM has seen an open or short to ground in the bypass cir- cuit, or a short to ground in the IC circuit.
  • Page 807 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 42 (3 of 3): Ignition Control (IC) Circuit (Scan) Grounded IC Circuit, Open Bypass Circuit, or Grounded Bypass Circuit STEP ACTION VALUE PROCEED TO Using a test light connected to battery positive (B+), probe ECM harness terminal J2-24 (CKT 424).

  • Page 808: Detected

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 43 (1 of 2): Knock Sensor (KS) Circuit (Scan) - Continuous Knock Detected FUSE 15A 485 GRN Knock Sensor Module To System Relay Starboard Knock Sensor Port Knock Sensor Knock Sensor Signal CIRCUIT DESCRIPTION: Knock Sensor (KS) system circuit is accomplished with a module that sends a voltage signal...
  • Page 809 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 43 (2 of 2): Knock Sensor (KS) Circuit (Scan) - Continuous Knock Detected STEP ACTION VALUE PROCEED TO Go to Was the “On-Board Diagnostic” (OBD) System – Step 2 System Check Performed? Check...
  • Page 810 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 44 (1 of 3): Knock Sensor (KS) Circuit (Scan) - No Knock Detected FUSE 15A 485 GRN Knock Sensor Module To System Relay Starboard Knock Sensor Port Knock Sensor Knock Sensor Signal CIRCUIT DESCRIPTION: Knock Sensor (KS) system circuit is accomplished with a module that sends a voltage signal...
  • Page 811 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 44 (2 of 3): Knock Sensor (KS) Circuit (Scan) - No Knock Detected TEST DESCRIPTION: Step 2. This step ensures the knock sensor circuitry is within the proper resistance value.
  • Page 812 TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 44 (3 of 3): Knock Sensor (KS) Circuit (Scan) - No Knock Detected STEP ACTION VALUE PROCEED TO 5. Using a test light connected to battery positive (B+), repeatedly touch knock sensor harness terminal (CKT 496).

  • Page 813: Code 51 (1 Of 1): Calibration Memory Failure (Scan)

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 51 (1 of 1): Calibration Memory Failure (Scan) 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM. This test is also used as a security measure to prevent improper use of calibrations or changes to these calibrations that may alter the designed function of EFI.

  • Page 814: Code 52 (1 Of 1): Eeprom Failure (Scan)

    TROUBLE CODE DIAGNOSTICS - 7.4L MPI SERVICE MANUAL NUMBER 23 Code 52 (1 of 1): EEPROM Failure (Scan) 72801 CIRCUIT DESCRIPTION: This test allows the ECM to check for a calibration failure by comparing the calibration value to a known value stored in the EEPROM. This test is also used as a security measure to prevent improper use of calibrations or changes to these calibrations that may alter the designed function of EFI.
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  • Page 826 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 COOLING SYSTEM Section 6A - Seawater Cooled Models Table of Contents Torque Specifications ....6A-2 Water Circulating Pump .

  • Page 827: Torque Specifications

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location lb-in. lb-ft Alternator Mounting Bracket Power Steering Pump Bracket Seawater Pump Brace Seawater Pump Bracket To Block Seawater Pump Cover Thermostat Cover Thermostat Housing Thru-Hull Pickup Nut Alternator To Mounting Bracket Water Circulating Pump Seawater Pump Clamping Screw On Casting Bracket Water Temperature Sender...

  • Page 828: Lubricants / Sealants / Adhesives

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Lubricants / Sealants / Adhesives Description Part Number Quicksilver Loctite 27131 92-809820 Quicksilver Perfect Seal 92-34227--1 Quicksilver 2-4-C Marine Lubricant With Teflon 92-825407A3 Quicksilver High Performance Gear Lube 92-816026A2 Quicksilver Liquid Neoprene 92-25711--3 Quicksilver Special Lubricant 101 92-13872A1 Loctite 22423...

  • Page 829: Seawater Inlet Recommendations

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Seawater Inlet Recommendations Transom Mounted or Through-Hull Seawater Pickups and Hose Water pickup must be large enough to permit sufficient water flow to engine seawater pickup pump for adequate engine cooling [30 gal. per min. (114 L per min.) minimum]. Pickup also must supply a positive head while underway.

  • Page 830: Seawater Pickups

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Seawater Pickups NOTICE Refer to manufacturer’s instructions for information on removal and installation of other than Quicksilver Seawater Pickups. IMPORTANT: Seal the inside edges of any hole made through the hull with a suitable sealant to prevent water absorption and deterioration.
  • Page 831 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Transom Mounted 72640 Hose Nipple Nut (4) Gasket - Between Pickup and Transom O-Ring (4) Washer (4) Bolt (4) Plastic Pug Pickup Screen Screw (2) 1. Seal the inside edges of the 1-1/2 in. (38 mm) hole hose nipple. 2.
  • Page 832 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 4. Place new gasket on pickup housing and hold pickup in place on transom. Install four round head bolt (with washers and O-rings in place) into pickup mounting holes and through drilled 21/64 in. (8 mm) holes in transom. NOTE: Some installations may have 7/32 in.

  • Page 833: Sea Strainer

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Sea Strainer NOTICE Refer to manufacturer’s instructions for information on removal and installation of other than Quicksilver Sea Strainer Removal CAUTION If boat is in water while working on seawater strainer, close seacock, if so equipped. If boat is not equipped with a seacock, remove and plug seawater inlet hose to pre- vent a siphoning action that may occur, allowing seawater to flow from the drain holes or removed hoses and enter boat.

  • Page 834: Installation

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 2. Remove outlet hose. Drain into a suitable container. 72643 Seawater Inlet Hose Seawater Strainer 3. Remove mounting bolts. Remove strainer. Installation IMPORTANT: Mount seawater strainer in a vibration-free location. Never mount it on the engine or transmission.

  • Page 835: Seawater Pickup Pump

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 3. Check drain plug and lens cover bolts. Tighten securely. Do not overtighten cover bolts or cover may warp and leak water into boat. 72644 Drain Plug Lens Cover Bolts (2, One Hidden In This View) 4.

  • Page 836: Seawater Pump Disassembly

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 1. Remove water hose, which runs between pump outlet and engine, and replace with another hose of same diameter, but approximately 3 ft (1 m) longer. Hose should be wire reinforced or of adequate wall thickness to prevent it from kinking when performing test. Clamp hose at pump outlet only.

  • Page 837: Seawater Pump Reassembly

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 2. Remove seawater pump body, quad ring and wear plate from bearing housing. 75275 Seawater Pump Body Wear Plate Bearing Housing Quad Ring (Not Shown In This View) 3. Remove the impeller from seawater pump body. Seawater Pump Reassembly 1.

  • Page 838: Seawater Pump Bearing Housing

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 3. Place quad ring in groove in seawater pump body. Quad Ring Seawater Pump 4. Align flats on impeller and bearing housing shaft, slide seawater pump body on shaft. NOTE: Reassembly of the pump requires the mounting bracket to be installed while per- forming the following step.
  • Page 839 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 2. Press hub off shaft with Universal Puller Plate and an arbor press. 72648 Universal Puller Plate 3. Puncture front oil seal with a tool and pry from bearing housing. 72649 4. Remove snap ring from bearing housing bore and press shaft and bearings out pulley end of housing.

  • Page 840: Cleaning And Inspection

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 5. If bearings require replacement, remove bearings from shaft with Universal Puller Plate and an arbor press. Bearings must be replaced, if removed. 72659 6. If rear seals require replacement, press seals from bearing housing with an appropriate tool.

  • Page 841: Reassembly

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Reassembly 1. Apply a thin coat of Loctite Type 27131 to outside diameter of two new bearing housing rear seals; then install seals in housing with seal lips facing impeller end. Press first seal in until it contacts and second seal until flush with housing.
  • Page 842 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 4. Pack bearings and cavity between bearings with Shell Alvania No. 2 Grease or substi- tute. Slide bearings and shaft into bearing housing bore and install snap ring. 72661 Shaft With Bearings 72658 Snap Ring 5.
  • Page 843 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 IMPORTANT: Be sure to support impeller end of pump shaft when installing pulley hub in next step to prevent placing a load on bearings. 6. Apply Quicksilver Special Lubricant 101 to pump shaft. Using an arbor press and appro- priate tool, press pulley hub onto pump shaft to dimension shown.

  • Page 844: Water Circulating Pump

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Water Circulating Pump Removal 1. Drain water from cylinder block. 2. Break loose circulating pump pulley attaching bolts. Do not remove bolts at this time. 3. Loosen alternator tensioner pulley, then pivot alternator inward and remove the serpen- tine drive belt.

  • Page 845: Drive Belt Tension Adjustment

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Drive Belt Tension Adjustment 1. Loosen 5/8 in. locking nut on adjustment stud. Leave wrench on adjustment stud. NOTE: Belt deflection is to be measured on the belt at the location that has the longest dis- tance between two pulleys.

  • Page 846: Flushing Seawater Cooling System

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Flushing Seawater Cooling System 454/502 Mag MPI and 8.2L MPI Engines (Except Horizon Model) If engine is operated in salty, polluted or mineral-laden waters, seawater cooling system should be flushed periodically (preferably after each use) with fresh water to reduce corro- sion and prevent the accumulation of deposits in the system.

  • Page 847: 454 Mag Mpi Horizon Models

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 CAUTION If boat is in the water, seacock (if equipped) must be left closed until engine is to be restarted to prevent water from flowing back into cooling system. If boat is not fitted with a seacock, water inlet hose must be left disconnected and plugged, to prevent water from flowing into cooling system and/or boat.

  • Page 848: Seawater Strainer

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Seawater Strainer NOTICE Refer to manufacturer’s instructions for information on checking and cleaning of other than Quicksilver Seawater Strainer WARNING When cleaning seawater strainer, close seacock, if so equipped. If boat is not equipped with a seacock, remove and plug seawater inlet hose to prevent a siphoning action that may occur, allowing seawater to flow from the drain holes or removed hoses.

  • Page 849: Cleaning And Inspection

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Cleaning and Inspection 1. Clean any debris from strainer housing. 2. Flush both strainer and housing with clean water. 3. Check gasket; replace when necessary (if it leaks). Reassembly 1. Reinstall strainer, drain plug and washer. 2.

  • Page 850: Testing

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Testing 1. Clean thermostat in soap and water to remove any deposits or debris. 2. Inspect thermostat for corrosion or other visible damage. 3. If thermostat is suspected of producing insufficient engine temperature, check thermo- stat for leakage by holding it up to a lighted background.

  • Page 851: Installation

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 IMPORTANT: When performing procedures “d”-“f,” water must be agitated thor- oughly to obtain accurate results. d. Plug in tester and observe temperature at which thermostat opens (thermostat drops off thread). Thermostat must open at specified temperature stamped on ther- mostat.

  • Page 852: Auxiliary Hot Water Heater Installation

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Auxiliary Hot Water Heater Installation IMPORTANT: When connecting a cabin heater or hot water heater, certain require- ments must be met: Supply hose (from engine to heater) and return hose (from heater to engine) MUST NOT EXCEED 5/8 in.

  • Page 853: Water Tap Locations For Propshaft Coolers

    SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 Water Tap Locations For Propshaft Coolers IMPORTANT: Tapping into the wrong location can cause the engine to vapor lock or run too cold. MIE (Inboard) Models Only: Splice into the port-side exhaust manifold water hose. This provides the temperatures and pressures required to cool the packing glands without damaging them.
  • Page 854 SEAWATER COOLED MODELS SERVICE MANUAL NUMBER 23 NOTE: Certain components in the following diagram may look different than on your particu- lar power package, but the water flow paths remain similar on all engines. Thermostat Housing Engine Circulating Pump Seawater Pickup Pump Seawater Inlet Engine Oil Cooler Exhaust Elbow...
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  • Page 856: Cooling

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 COOLING SYSTEM Section 6B - Closed Cooled (Fresh Water) Models Table of Contents Torque Specifications ....6B-2 Thermostat .

  • Page 857: Torque Specifications

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location lb-in. lb-ft Heat Exchanger End Cap 36-72 Thermostat Cover Heat Exchanger Mounting Brackets Hose Clamps Securely Drain Plugs Lubricants / Sealants / Adhesives Description Part Number Quicksilver 2-4-C Marine Lubricant With 92-825407A3 Teflon Quicksilver Perfect Seal...

  • Page 858: Description

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Description There are several configurations of this cooling system, but the operation is essentially iden- tical. Basically, the system is composed of two separate subsystems: the seawater system and the closed cooling system. The seawater system is similar in function to the fan used in an automobile because it absorbs heat (from the closed cooling system) as it passes through the heat exchanger.

  • Page 859: Pressure Cap Maintenance

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 IMPORTANT: ALCOHOL OR METHANOL BASE ANTIFREEZE OR PLAIN WATER ARE NOT RECOMMENDED FOR USE IN COOLING SYSTEM AT ANY TIME. In areas where ethylene glycol is not available, and the possibility of freezing does not exist, it is permissible to use a solution of rust inhibitor and pure, soft water (mixed to manufacturer’s recommendations).

  • Page 860: Seawater Pickup Pump Maintenance

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 8. Clean coolant recovery passage in heat exchanger filler neck with a wire and blow out with compressed air. 72715 Inspect For Damage Clean Coolant Recovery Passages 9. Reinstall pressure cap, being sure to tighten until it contacts stops on filler neck. Seawater Pickup Pump Maintenance Whenever insufficient water flow is suspected, seawater pickup pump should be disas- sembled and inspected by an authorized MerCruiser Dealer.

  • Page 861: Pressure Testing System

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Pressure Testing System WARNING Allow engine to cool before removing pressure cap. Sudden loss of pressure could cause hot coolant to boil and discharge violently. After engine has cooled, turn cap 1/4 turn to allow any pressure to escape slowly, then push down and turn cap all the way off.

  • Page 862: Testing For Cylinder Head Gasket Leak

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 c. Drain oil from engine and examine for presence of coolant. Oil usually will be milky if coolant is present. If coolant is present, remove engine from boat and drop the oil pan.

  • Page 863: Testing Heat Exchanger

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Testing Heat Exchanger FOR INTERNAL LEAK An internal leak will cause coolant to go into the seawater circuit when pressure is put on the closed cooling circuit. 1. Remove a seawater hose from the exchanger. Do not drain the exchanger. 2.
  • Page 864 CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 5. Using a cooling system pressure tester (similar to one shown), test cap to be sure that it releases at proper pressure and does not leak. (Refer to instructions which accompa- ny tester for correct test procedure.) Cap must relieve pressure at 16 PSI (110 kPa), and must hold rated pressure for 30 seconds without going below 11 PSI.

  • Page 865: Thermostat

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Thermostat Removal NOTE: If coolant flow is restricted or fails to occur, a wire should be repeatedly inserted into all drain holes to ensure there are no obstructions in passages. Remove petcock, if neces- sary, to insert wire completely into drain hole.

  • Page 866: Testing

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Testing 1. Clean thermostat in soap and water to remove any deposits or debris. 2. Inspect thermostat for corrosion or other visible damage. 75747 3. If thermostat is suspected of producing insufficient engine temperature, check thermo- stat for leakage by holding it up to lighted background.

  • Page 867: Installation

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Installation CAUTION Avoid seawater pickup pump impeller damage. DO NOT operate engine without cooling water being supplied to seawater pickup pump. 1. Remove thermostat housing and gaskets. Discard gaskets. 2. Clean gasket surfaces on thermostat cover, thermostat housing and intake manifold. 3.

  • Page 868: Changing Coolant

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Changing Coolant NOTICE For information and procedures on draining the seawater cooling system of Seawa- ter Cooled (Raw-water) Cooled Models, refer to SECTION 6A. For information and procedures on draining the Seawater Section of Closed Cooling (Coolant) Models refer to SECTION 1B.

  • Page 869: Cleaning System

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 IMPORTANT: Engine must be as level as possible to ensure complete draining of cooling system. IMPORTANT: Closed cooling section must be kept filled year round with recom- mended coolant. If engine will be exposed to freezing temperatures, make sure closed cooling section is filled with Extended Life 5/100 Coolant or an ethylene glycol antifreeze and water solution properly mixed to protect engine to lowest temperature to which it will be exposed.

  • Page 870: Seawater Section

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Seawater Section Cooling efficiency of an engine with closed cooling is greatly dependent upon heat transfer through the tubes within the heat exchanger. During engine operation, contaminants within the seawater (such as salt, silt, lime, etc.) collect on the inside of the tubes, thus reducing heat transfer and greatly decreasing heat exchanger efficiency.

  • Page 871: Filling Closed Cooling Section

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Filling Closed Cooling Section CAUTION Alcohol or Methanol base antifreeze or plain water are not recommended for use in coolant section of Closed Cooling System at any time. It is recommended that coolant section of Closed Cooling System be filled with a 50/50 mix- ture of Extended Life 5/100 Coolant and pure, soft water.
  • Page 872 CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 2. Start engine and run AT IDLE. Add coolant solution to heat exchanger, as required, to maintain coolant level at filler neck. After engine has reached normal operating tempera- ture (thermostat is fully open), and coolant level remains constant, fill heat exchanger until coolant level is into filler neck and begins to flow into coolant recovery bottle plastic tubing.

  • Page 873: Auxiliary Hot Water Heater Installation

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Auxiliary Hot Water Heater Installation IMPORTANT: When connecting a cabin heater or hot water heater, certain require- ments must be met: Supply hose (from engine to heater) and return hose (from heater to engine) MUST NOT EXCEED 5/8 in.

  • Page 874: Heat Exchanger Bracket Hardware

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Heat Exchanger Bracket Hardware 71495 71494 74791 Typical MIE (Inboard) Engine Shown, All Similar Starboard Thermostat Housing-To-Heat Exchanger Hose Port Thermostat Housing-To-Heat Exchanger Hose Engine Water Circulating Pump-To-Heat Exchanger Hose Upper Alternator Bracket And Fuel Line Clip Screw Heat Exchanger Bracket Large Diameter Washer Spacer...

  • Page 875: Heat Exchanger Hose Connections

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Heat Exchanger Hose Connections 74073 74789 74073 74788 MIE (Inboard) Engine Shown, All Similar Heat Exchanger Large Hose Clamps Starboard Heat Exchanger-To-Exhaust Manifold Hose Port Heat Exchanger-To-Exhaust Manifold Hose Oil Cooler-To-Heat Exchanger Hose Coolant Identification Decal Bypass Hose (Back Side Of Heat Exchanger) Index...

  • Page 876: Closed Cooling System Water Flow Diagram

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Closed Cooling System Water Flow Diagram MCM / MIE Models 75748 Seawater Intake Power Steering Cooler (MCM) or Transmission Cooler (MIE) Fuel Cooler Heat Exchanger Thermostat Housing and Cover Assembly Engine Water Circulating Pump Engine Block and Cylinder Head Assembly Exhaust Manifold Exhaust Elbow...

  • Page 877: (Coolant Section Of System)

    CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 Draining Diagram (Coolant Section of System) 75005 Remove Hoses (Lift, Lower or Bend To Completely Drain). Remove Block Plugs (Repeatedly Clean Out Holes Using A Stiff Wire Until Entire System Is Drained). Index Page 6B-22 90-861326--1 MARCH 1999...
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  • Page 879 CLOSED COOLED (FRESH WATER) MODELS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 6B-24 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 880 GENERAL SERVICE MANUAL NUMBER 23 EXHAUST SYSTEM Section 7A - General Table of Contents Exhaust System Requirements ..7A-2 MIE (Inboard) Engines ....7A-3 Determining If Exhaust Elbow Risers Exhaust Hose Connection...

  • Page 881: Exhaust System Requirements

    4. Exhaust outlet must be slightly above the waterline with boat at rest in the water and full load aboard. 5. Back pressure must not exceed 4 in. (102 mm) of mercury when measured with a mercury manometer to exhaust elbow outlets.

  • Page 882: Mie (Inboard) Engines

    5. System must not cause excessive back pressure. Back pressure MUST NOT exceed 4 in. (102 mm) of mercury when measured with a mercury manometer at exhaust elbow outlets. Minimum exhaust hose sizes are given in chart.

  • Page 883: Exhaust Tube Requirements

    GENERAL SERVICE MANUAL NUMBER 23 Exhaust Tube Requirements IMPORTANT: When installing thru-transom exhaust, it is recommended that the exhaust bellows on the transom assembly be removed. This is necessary to avoid creating a vacuum at the exhaust outlet in the propeller at higher boat speeds. This vacuum could degrade propeller performance on some boats.
  • Page 884 GENERAL SERVICE MANUAL NUMBER 23 2. If required, install exhaust tube on gimbal housing as follows: a. Remove and discard clamps and exhaust bellows. CAUTION Exhaust tube clamp may corrode if grounding clip is not installed. b. Install grounding clip on tube. NOTE: Bellows adhesive is not used when installing an exhaust tube.
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  • Page 886 MANIFOLDS AND ELBOWS SERVICE MANUAL NUMBER 23 EXHAUST SYSTEM Section 7B - Manifolds And Elbows Table of Contents Torque Specifications ....7B-2 Cleaning .

  • Page 887: Torque Specifications

    MANIFOLDS AND ELBOWS SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location lb-ft Hose Clamp Securely Exhaust Elbow Exhaust Manifold Lubricants / Sealants / Adhesives Description Part Number Quicksilver Perfect Seal 92-34227--1 Removal WARNING Avoid possible injury or damage to equipment should wires be accidentally shorted.

  • Page 888: Cleaning

    MANIFOLDS AND ELBOWS SERVICE MANUAL NUMBER 23 7. Remove exhaust manifold fasteners. Remove manifold assembly and discard gaskets. 75749 Exhaust Elbow Restrictor Gasket Open Gasket (Later Models) Exhaust Manifold Bolts Cleaning 1. Clean gasket material from all surfaces and wash parts in solvent. 2.

  • Page 889: Installation

    MANIFOLDS AND ELBOWS SERVICE MANUAL NUMBER 23 Installation IMPORTANT: See SECTION 7C if exhaust risers are used. 1. Using new gasket, install exhaust manifold to cylinder head. Torque fasteners to 25 lb-ft (34 Nm). 2. Using a new gasket, install exhaust elbow to exhaust manifold. Torque fasteners to 25 lb-ft (34 Nm).
  • Page 890 MANIFOLDS AND ELBOWS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 7B-5 Downloaded from https://needmanual.com/...
  • Page 891 RISERS SERVICE MANUAL NUMBER 23 EXHAUST SYSTEM Section 7C - Risers Table of Contents Description ......7C-2 Maintenance Instructions .

  • Page 892: Description

    RISERS SERVICE MANUAL NUMBER 23 Description The exhaust riser is designed to increase the height of the exhaust elbow. This allows boats with a low mounted engine package to meet the minimum exhaust system height require- ments. Torque Specifications Fastener Location Lb.

  • Page 893: Exhaust Risers

    RISERS SERVICE MANUAL NUMBER 23 Exhaust Risers Removal 1. Remove any items attached to the elbows on the engine and carefully lay them aside. Remember their positioning for reassembly later. 2. Remove fasteners retaining exhaust elbows and risers to manifolds and retain. Remove exhaust elbows.

  • Page 894: Exhaust Extension

    RISERS SERVICE MANUAL NUMBER 23 IMPORTANT: On elbows with shift plate (MCM only) reinstall shift plate and tighten fasteners securely, then readjust shift cables as outlined in appropriate Sterndrive Service Manual. 7. Assemble harness bracket and plastic backup plate, if equipped, using four small screws.

  • Page 895: Maintenance Instructions

    RISERS SERVICE MANUAL NUMBER 23 Maintenance Instructions Maintenance inspection is owner’s responsibility and must be performed at intervals speci- fied in owner’s “Operation and Maintenance Manual”. 1. Check to ensure exhaust elbow and manifold fasteners are adequately tightened. 2. Check to ensure hose clamps are adequately tightened. 3.

  • Page 896: Cast Iron Elbows With 3 Inch Riser And Muffler Spacer

    RISERS SERVICE MANUAL NUMBER 23 Cast Iron Elbows With 3 Inch Riser and Muffler Spacer 70622 Exhaust Elbow Muffler Spacer 1-1/4 Inch (32 mm) Open Gasket Exhaust Riser 3 Inch (76 mm) Separator Gasket Restrictor Gasket Nut (8) Stud (8) 9-3/8 Inch (238 mm) Stud (8) 10-3/8 Inch (264 mm) Used With Remote Oil Filter Washer (8) Exhaust Manifold...

  • Page 897: Cast Iron Elbows With 6 Inch Riser

    RISERS SERVICE MANUAL NUMBER 23 Cast Iron Elbows With 6 Inch Riser 70482 Exhaust Elbow 4 In. (101 mm) Restrictor Gasket Exhaust Riser 6 In. (152 mm) Open Gasket (4 Slots) Bolt (8) 6 In. (152 mm) or Bolt (2) 7 In. (178 mm) (Used Only at Remote Oil Filter Bracket if Equipped) Hex Head Screw (4) 1 In.

  • Page 898: Cast Iron Elbows With 6 Inch Riser And Mufflers

    RISERS SERVICE MANUAL NUMBER 23 Cast Iron Elbows With 6 Inch Riser and Mufflers 70481 Exhaust Elbow 4 In. (101 mm) Muffler Spacer 1-1/4 In. (32 mm) Exhaust Riser 6 In. (152 mm) Open Gasket (4 Slots) Hex Head Screw (4) 1 In. (25 mm) Bolt (8) 7 In.
  • Page 899 RISERS SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 7C-9 Downloaded from https://needmanual.com/...
  • Page 900 COLLECTORS SERVICE MANUAL NUMBER 23 EXHAUST SYSTEM Section 7D - Collectors Table of Contents Torque Specifications ....7D-2 Silent Choice Exhaust System ..7D-7 Lubricants/Sealants/Adhesives .

  • Page 901: Torque Specifications

    COLLECTORS SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location Lb. In. Lb. Ft. N·m Block-Off Plate Exhaust Pipe to Gimbal Housing Exhaust Pipe to Tee Pipe 20 25 20-25 27 34 27-34 Tee Pipe to Gimbal Housing Upper Exhaust Pipe to Lower Exhaust Pipe Exhaust Elbow Air Pump Mount Muffler End Plate...

  • Page 902: Shutter Replacement

    COLLECTORS SERVICE MANUAL NUMBER 23 Shutter Replacement IMPORTANT: Engine does not have to be removed to change shutters. 1. Loosen clamps and remove exhaust pipe, elbow and exhaust hose. 2. Replace water shutter as shown. 3. Reinstall pipe, elbow and hose. Tighten clamps securely. 75760 Exhaust Flapper Rubber Grommets...

  • Page 903: Component Replacement

    COLLECTORS SERVICE MANUAL NUMBER 23 Component Replacement To replace any components in exhaust system, the following must be adhered to: All mating surfaces must be clean. O-ring must remain in groove to properly seal joints to prevent leakage. Torque all bolts to 20-25 lb. ft. (27-34 N·m). Tighten all clamps securely.

  • Page 904: Through-Transom Exhaust

    COLLECTORS SERVICE MANUAL NUMBER 23 Thru-Transom Exhaust Shutter Replacement IMPORTANT: A block off plate must be installed when using thru-transom exhaust or below swim platform kits. 22057 Block Off Plate Bolts (4) 1. Remove exhaust hose clamps, then hose. 2. Chisel rivets away from both support members. 27761 Shutter Hinge Water Shutter - Opens Toward Outside Of Boat...

  • Page 905: Component Replacement

    COLLECTORS SERVICE MANUAL NUMBER 23 Component Replacement 72740 Transom Exhaust Kit Screw And Nut (4) Support Member Water Shutter (Hinge Must Be Vertical) Gasket Exhaust Flange Bolts, Washers and Nuts (3) Clamp Cover (Flapper) Below Swim Platform Exhaust Pipe This exhaust kit may be used on any MerCruiser installation having a 4 in. (102 mm) exhaust elbow.

  • Page 906: Silent Choice Exhaust System

    COLLECTORS SERVICE MANUAL NUMBER 23 The below swim platform exhaust pipe can be modified for specific height applications by cutting pipe at location shown. 72743 Cut Line (See Notes) To Engine To Transom NOTE: If riser kits are installed, or if more vertical drop is required, cut “a” must be made, and the upper and lower sections of the pipe rejoined with a 4 in.

  • Page 907: Exhaust Tube Installation

    COLLECTORS SERVICE MANUAL NUMBER 23 Exhaust Tube Installation 1. If required, remove and discard clamps and bellows from gimbal housing. 22116 2. If required, install exhaust tube on gimbal housing as follows: 3. Remove and discard clamps and exhaust bellows. CAUTION Exhaust tube clamp may corrode if grounding clip is not installed.
  • Page 908 COLLECTORS SERVICE MANUAL NUMBER 23 (1.) Position tube so that “SIDE” markings on tube are facing toward the right and left sides. (2.) Install clamp. (3.) Tighten clamp securely. 22184 22184 Exhaust Tube Clamp “Side” Marking Exhaust Tube Grounding Clip 72539 Silencer Valve Assembly Hose Clamps...

  • Page 909: Air Tube Routing

    COLLECTORS SERVICE MANUAL NUMBER 23 Air Tube Routing 1. Route air tubing from air pump to silencer valve cylinders. Do not route air tubing close to hot surfaces. Excessive heat will damage air tubes. 72775 Single Engine Air Tube T-Fittings Air Pump Assembly Air Tube To Air Cylinder - On Each Silencer Valve 72776...

  • Page 910: Maintenance

    COLLECTORS SERVICE MANUAL NUMBER 23 Maintenance 1. Air Intake Filter (32-17272) must be checked once each year. If filter is clogged or partially clogged, replace. The filter pad is glued in, and may be removed with a needle-nose pliers. Clean surface in casting, apply a single dot of Quicksilver Sound Blanket Glue to center of casting, and install new filter.

  • Page 911: Exhaust Muffler Kit

    7 degrees downward outlets), requires the installation of 1-1/4 in. (32 mm) exhaust elbow risers, which are included in the kit. IMPORTANT: If a thru-transom exhaust kit other than the one from Mercury Marine is used, the exhaust kit must be equipped with internal shutters and external flap- pers.

  • Page 912: Cleaning And Inspection

    COLLECTORS SERVICE MANUAL NUMBER 23 IMPORTANT: Restrictor gaskets (if equipped) must be installed in order shown. 72780 1-1/4 Inch Muffler Riser Installation Exhaust Manifold Exhaust Elbow Bolt (4 Each Manifold) Gasket - Lightly Coat Both Sides With Quicksilver Perfect Seal Riser 1-1/4 Inch (32 mm) Height Restrictor Gasket (Open Gasket on Later Models) Refer To Note Following...

  • Page 913: Installation

    COLLECTORS SERVICE MANUAL NUMBER 23 Installation 1. Install muffler, as shown, into exhaust hose and molded tube. Fabricate muffler to tran- som using 4-inch I.D. exhaust hose, cut to required length. NOTE: Removable end of muffler ALWAYS goes toward exhaust elbow. This places direc- tion marks on muffler body casting at the upper rear corner on the port side.
  • Page 914 COLLECTORS SERVICE MANUAL NUMBER 23 4. As needed, depending on use conditions, remove mufflers, then remove four screws securing forward end plate, and remove end plate and element and interior of muffler. Clean thoroughly, at least once each year, using pressurized water. 72782 Removable End Plate 4 Screws Secure End Plate...
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  • Page 916 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 DRIVES Section 8A - Velvet Drive In-Line Transmission Table of Contents Velvet Drive In-Line (72C) Specifications 8A-2 Shift Cable Adjustment ....8A-5 Transmission Ratios .

  • Page 917: Velvet Drive In-Line (72C) Specifications

    VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Velvet Drive In-Line (72C) Specifications The transmission identification plate is located on the top left side of the transmission. Refer to charts following to determine engine and transmission combinations 72839 Transmission Identification Plate Model Number Ratio (In Forward Gear) Serial Number...
  • Page 918 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Transmission Fluid Capacities MODEL U.S. QTS. (LITRES) 1-1/2 (1.3) 72C Reduction 2-1/2 (2.4) Use dipstick to determine fluid exact level. Warm Fluid Level Check: The transmission should be at operating temperature [190 F (90 C) maximum] to receive an accurate oil level reading.
  • Page 919 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Engine Engine rotation is indicated on engine specifications and serial number decal on flame arrestor cover. Engine rotation is described when observed from the rear of the engine (transmission end) looking forward (water pump end). Installed angle of MIE inboard transmission and engine should not exceed a maximum of 18 of the water line.
  • Page 920 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Transmission Shift Lever The lever has three holes as illustrated following. The shift lever stud is placed in the forward hole when using Quicksilver remote control cables. 71301 Stud In This Hole Shift Cable Adjustment Refer to SECTION 2C - “MIE Models - Velvet Drive Transmissions”...
  • Page 921 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Changing Transmission Fluid Draining Transmission 1. Clean area around cooler hose shown and proceed as follows: a. Disconnect hose from elbow fitting. b. Remove elbow fitting from bushing. c. Drain oil from transmission, cooler and cooler hoses into a suitable container. 72840 Transmission With 1:1 Ratio Hose...
  • Page 922 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 3. Clean strainer tube in suitable solvent. 71307 Bushing Spring Plastic Strainer Tube 4. Check oil for the following foreign matter: Metal Particles - A few small particles are normal. Larger metal chips are an early sign of transmission failure which may mean transmission should be disassembled and in- spected for internal damage.
  • Page 923 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Filling Transmission IMPORTANT: Use only specified transmission fluid (see “Specifications”). 1. Remove dipstick. Fill transmission with fluid, through dipstick hole, to bring up to full mark. 72526 Dipstick Full Mark Dipstick Tube IMPORTANT: To accurately check fluid level, run engine at 1500 RPM for 2 minutes immediately prior to checking level.
  • Page 924 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Removal and Installation NOTICE The following procedure describes removal of transmission without removing en- gine. If engine must be removed, refer to Section 2 (see “Table of Contents”). 1. Drain transmission fluid. 2.
  • Page 925 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 22. Connect and adjust shift cable(s) as outlined in SECTION 2C, “MIE Models - Velvet Drive Transmissions”. IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner, or if remote control and shift cable do not position shift lever exactly as shown.
  • Page 926 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 Shift Lever Installation IMPORTANT: Velvet Drive Warranty is jeopardized if the shift lever poppet spring and/ or ball is permanently removed, or if the shift lever is changed in any manner, or repo- sitioned, or if the linkage between the remote control and the transmission shift lever does not have sufficient travel in both directions.
  • Page 927 3. Refer to “Specifications” for pressure readings. Transmission Repair Mercury Marine does not stock or sell replacement parts for the in-line transmission. Velvet Drive has a network of distributors throughout the world to service their product. These dis- tributors, in turn, have a dealer network to service the transmissions. Also, service manuals (for each transmission) can be obtained from Velvet Drive.
  • Page 928 VELVET DRIVE IN-LINE TRANSMISSION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index 90-861326--1 MARCH 1999 Page 8A-13 Downloaded from https://needmanual.com/...
  • Page 929 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 DRIVES Section 8B - Velvet Drive 5000A Down Angle Transmission Table of Contents Identification ......8B-2 Shift Cable Adjustment .
  • Page 930 Transmission Identification Plate Model Number Ratio (In Forward) Serial Number Identification Plate Model Color Code Transmission Ratios and Part Numbers Ratio in Forward Identification Plate Velvet Drive Model Mercury Marine Part Gear Color Code Number Number 1.5:1 20-01-003 805495A6 20-01-004...

  • Page 931: Torque Specifications

    VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Torque Specifications Item / Fastener Location Lb. In. Lb. Ft. Drain Plug Fluid Hose-to-Cooler Fluid Hose-to-Housing Rear Mounts-to-Transmission Shift Lever-to-Valve 96-132 11-15 Transmission-to-Flywheel Hous- Neutral Start Safety Switch Propeller Shaft Coupler To Out- put Flange Transmission Fluid Type Obtain Locally...
  • Page 932 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Important Information Engine Engine rotation is indicated on engine specifications and serial number decal on the engine. Engine rotation is described when observed from the rear of the engine (transmission end) looking forward (water pump end).
  • Page 933 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Transmission / Propeller Rotation Velvet Drive 5000A - 8 Down Angle Transmission: These transmissions are “full power reversing” transmissions, allowing a standard (LH rotation) engine to be used for both propeller rotations.
  • Page 934 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 For Left-Hand Propeller Shaft Rotation: Shift cable hookup at remote control must result in shift cable end guide moving in direction “A” when remote control handle is placed in for- ward position.
  • Page 935 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner, or if remote control and shift cable do not position shift lever exactly as shown.
  • Page 936 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Transmission Shift Lever and Shift Cable Bracket 1. The lever has three holes as illustrated following. For use with Quicksilver shift cables, the anchor stud is located in the middle hole. 73249 Shift Lever Shift Cable Anchor Stud Location (For Quicksilver Shift Cables)
  • Page 937 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Shift Cable Adjustment IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner or if remote control and shift cable do not position shift lever exactly as shown.
  • Page 938 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 IMPORTANT: The Velvet Drive 5000A is a full reversing transmission. Direction of out- put/propeller rotation is determined by hookup of shift cable at remote control. 73291 Position Is Forward Gear For LH Rotation Propeller Input Output Output Shaft...
  • Page 939 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 IMPORTANT: Be certain anchor stud is installed in the front hole as shown in the illus- tration following. 73284 Anchor Stud In Front Hole Shift Cable Bracket Remote control must provide a total shift cable travel (at transmission end) of at least 2-3/4 in.
  • Page 940 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 1. Place remote control shift lever and transmission shift lever in neutral position. 2. Remove nuts and washers from shift cable attaching studs. 3. Locate center of remote control and control shift cable play (backlash) as follows: a.
  • Page 941 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 CAUTION Remote control and shift cable must position transmission shift lever exactly as shown, or transmission failure may occur. Do not remove poppet ball or spring. 73248 Transmission Shift Lever Poppet Ball Must Be Centered in This Detent Hole when Left-Hand Propeller Shaft Rotation Is Desired Poppet Ball Must Be Centered in This Detent Hole when Right-Hand Propeller...
  • Page 942 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 10. Install nut and washer to cable barrel stud. Tighten until they bottom out. Tighten securely, but DO NOT OVER-TIGHTEN. 71972 71780 Typical Single Cable Installation - Rear Approach Cable End Guide Spacer (As Required) Elastic Stop Nut And Washer Bushing(s)
  • Page 943 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Checking Transmission Fluid Level IMPORTANT: Use only specified transmission fluid (see “Specifications”). Check transmission fluid before running engine each day, as follows: 1. Remove dipstick. Check fluid level as indicated on dipstick. Fluid level may be some- what over full mark, as some of the fluid from transmission fluid cooler and hoses may have drained back into transmission.
  • Page 944 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Changing Transmission Fluid Draining Transmission 1. Clean area around drain plug shown. 2. Remove dipstick and then remove drain plug. Drain oil from transmission into a suitable container. 73252 Drain Plug 3.
  • Page 945 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Filling Transmission IMPORTANT: Use only specified transmission fluid (see “Specifications”). 1. Remove dipstick. Fill transmission with fluid, through dipstick hole, to bring up to full mark. 73250 Dipstick Full Mark Dipstick Tube IMPORTANT: To accurately check fluid level, run engine at 1500 RPM for 2 minutes immediately prior to checking level.
  • Page 946 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 9. Support transmission with hoist or by other suitable means through the lifting eye on the transmission case. 10. Remove port and starboard rear mount brackets (with base and trunnion) from transmis- sion.
  • Page 947 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 8. Connect and adjust shift cable(s). IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner, or if remote control and shift cable do not position shift lever exactly as shown.
  • Page 948 VELVET DRIVE 5000A DOWN ANGLE TRANSMISSION SERVICE MANUAL NUMBER 23 Shift Lever Installation IMPORTANT: Velvet Drive Warranty is jeopardized if the shift lever poppet spring and/ or ball is permanently removed, or if the shift lever is changed in any manner, or repo- sitioned, or if the linkage between the remote control and the transmission shift lever does not have sufficient travel in both directions.
  • Page 949 3. Refer to “Operating Specifications” for test RPMs and respective pressure readings. Transmission Repair Mercury Marine does not stock or sell replacement parts for the down angle transmission. Velvet Drive has a network of distributors throughout the world to service their product.
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  • Page 951 VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 DRIVES Section 8C - Velvet Drive 5000V V-Drive Transmission Table of Contents Identification ......8C-2 Shift Cable Adjustment .
  • Page 952 Transmission Identification Plate Model Number Ratio (In Forward Gear) Serial Number Identification Plate Model Color Code Transmission Ratios and Part Numbers Ratio in For- Identification Plate Velvet Drive Model Mercury Marine ward Gear Color Code Number Part Number 1.5:1 20-02-003 807481A5 Blue...

  • Page 953: Important Information

    VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Transmission Fluid Capacities MODEL U.S. QTS. (LITERS) 5000V 3 (2-3/4) Use dipstick to determine fluid exact level. Warm Fluid Level Check: The transmission should be at operating temperature [190 F(90 C)] maximum to receive an accurate oil level reading.

  • Page 954: Transmission

    VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Transmission Transmission gear ratio (in forward gear) is marked on transmission identification plate, which is located on the port (left) side of transmission. 1. DO NOT start or crank engine without fluid in transmission. 2.

  • Page 955: Shift Cable Adjustment

    VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Shift Cable Adjustment IMPORTANT: Velvet Drive Transmission Warranty is jeopardized if the shift lever pop- pet ball or spring is permanently removed, if the shift lever is repositioned or changed in any manner or if remote control and shift cable do not position shift lever exactly as shown.
  • Page 956 VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 IMPORTANT: Be certain anchor stud is installed in the front hole as shown in the illus- tration following. 73284 Anchor Stud In Front Hole Shift Cable Bracket Remote control must provide a total shift cable travel (at transmission end) of at least 2-3/4 in.
  • Page 957 VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 10. Locate center of remote control and control shift cable play (backlash) as follows: a. Check that remote control is in neutral position. b. Push in on control cable end with enough pressure to remove play; mark position (a) on tube.
  • Page 958 VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 CAUTION Remote control and shift cable must position transmission shift lever exactly as shown, or transmission failure may occur. Do not remove poppet ball or spring. 73248 Transmission Shift Lever Poppet Ball Must Be Centered in This Detent Hole when Left-Hand Propeller Shaft Rotation Is Desired Poppet Ball Must Be Centered in This Detent Hole when Right-Hand Propeller Shaft Rotation Is Desired...
  • Page 959 VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 17. Install nut and washer to cable barrel stud. Tighten until they contact. Tighten securely, but DO NOT OVER-TIGHTEN. 71780 71972 Typical Single Cable - Rear Approach Cable End Guide Thick Spacer Thin Spacer Elastic Stop Nut and Washer Cable Barrel (Position Only Indicated In Lower Drawing)

  • Page 960: Checking Transmission Fluid Level

    VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Checking Transmission Fluid Level IMPORTANT: Use only specified transmission fluid (see “Specifications”). Check transmission fluid before starting engine each day, as follows: 1. Remove dipstick. Check fluid level as indicated on dipstick. Fluid level may be some- what over full mark, as some of the fluid from transmission fluid cooler and hoses may have drained back into transmission.

  • Page 961: Changing Transmission Fluid

    VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Changing Transmission Fluid Draining Transmission 1. Clean area around drain plug shown. 2. Remove dipstick and then remove drain plug. Drain oil from transmission into a suitable container. 74604 Typical MIE Transmission Drain Plug 3.

  • Page 962: Filling Transmission

    VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Filling Transmission IMPORTANT: Use only specified automatic transmission fluid (see “Specifications”). 1. Remove dipstick. Fill transmission with fluid, through dipstick hole, to bring up to full mark. 73250 Dipstick Full Mark Dipstick Tube IMPORTANT: To accurately check fluid level, run engine at 1500 RPM for 2 minutes immediately prior to checking level.
  • Page 963 VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 10. Remove remaining transmission attaching bolts. 11. Pull transmission straight back and off engine. Installation 1. Before installing transmission, check transmission pump indexing for correct rotation. Refer to “Pump Indexing.” 2. Check transmission output shaft rolling torque. See “Specifications.” 3.

  • Page 964: Shift Lever Installation

    VELVET DRIVE 5000V V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 13. Refer to SECTION 2C, “MIE Models - Velvet Drive Transmissions” and check engine final alignment as outlined. 14. After engine has been properly aligned, connect propeller shaft coupler to transmission output flange.

  • Page 965: Pressure Test

    Transmission Repair V-Drive Mercury Marine does not stock or sell replacement parts for the V-drive transmission. Velvet Drive has a network of distributors throughout the world to service their product. These dis- tributors, in turn, have a dealer network to service the transmissions. Also, service manuals (for each transmission) can be obtained from Velvet Drive.
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  • Page 967 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 DRIVES Section 8D - Hurth V-Drive Transmission Table of Contents Identification ......8D-2 Shift Cable Installation and Adjustment .
  • Page 968 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 Identification The transmission identification plate is located on the top rear of the transmission. HSW 630V – 1,5 Getr.-Nr. = 1,56 = 1,58 71039 MADE IN WEST-GERMANY 72959 Late Style Identification Plate Serial Number and Gear Ratio Torque Specifications Item / Fastener Location Lb.
  • Page 969 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Tools Description Specification Thermometer [(3/8 In, Thread 0-270 F (-18 to -132 C)] Obtain Locally Pressure Gauge (M10x1 Thread) Lubricants/Sealants Description Specification Quicksilver Engine Coupler Spline Grease 92-816391A4 Quicksilver Liquid Neoprene 92-25711--3 ATF Dexron lll Loctite Type A Obtain Locally Loctite 515...
  • Page 970 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 IMPORTANT: Transmission propeller rotation is determined by the shift cable instal- lation in the remote control. RIGHT-HAND PROPELLER ROTATION - Control cable will have to be installed in re- mote control so that cable end will move in direction “A” when shift handle is placed in the forward position.
  • Page 971 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 1. On bracket with two anchor location holes: Be certain anchor stud is installed in the hole marked “630.” WARNING Avoid serious personal injury or property damage caused by improper shifting. Anchor stud for shift cable must be installed in the correct hole when using bracket with two anchor location holes.
  • Page 972 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 5. Center cable-end play, then adjust cable barrel to align holes in barrel and in cable end guide with attaching points on transmission. 6. Temporarily install shift cable. Do not secure at this time. IMPORTANT: Transmission is fully in gear when shift lever comes to a stop, in either direction.
  • Page 973 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 11. Install nut and washer to cable barrel stud. Tighten until they contacts. Then loosen 1/2 turn. 50229 Cable End Guide Locknut and Washer (Tighten Until Bottoms Out, Then Loosen 1/2 Turn) Spacer Bushings Cable Barrel 12.
  • Page 974 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 72957 50229 Typical Single Cable - Rear Approach Cable End Guide Locknut And Washer (Tighten Until Bottoms Out, Then Loosen 1/2 Turn) Spacer (Fits Over Bushings) Bushing Cable Barrel Cable Barrel Stud Cable End Guide Stud 71211 72956 Typical Dual Cable - Forward Approach...
  • Page 975 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 50073 72960 Typical Dual Cable - Rear Approach Cable End Guide Locknut And Washer (Tighten Until Bottoms Out, Then Loosen 1/2 Turn) Spacer (Fits Over Bushings) Bushing Cable Barrel Spacers (Fits Over Stud) Cable Barrel Stud Cable End Guide Stud Index...
  • Page 976 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 Checking Transmission Fluid Level IMPORTANT: Use only specified transmission fluid (see “Lubricants/Sealants”). IMPORTANT: The dipstick to check fluid level is located on the port side of transmis- sion. DO NOT remove T-handle on starboard side of transmission. Check transmission fluid before starting engine each day, as follows: 1.
  • Page 977 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Draining Transmission 1. Clean the exterior of transmission before disassembly. NOTE: Later model Hurth transmissions will be equipped with an allen head socket screw on the oil filter cover. 2. Remove oil filter from housing by turning (counterclockwise) and pulling at the same time.
  • Page 978 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 Filling Transmission IMPORTANT: Use only Automatic Transmission Fluid (ATF) as recommended in “Lubricants/Sealants.” 1. Fill transmission to proper level, through oil filter cavity. (Refer to “Capacity.”) 2. Install filter as follows: a. Coat O-ring on filter cover with transmission fluid. 27662 Filter Cover O-Ring...
  • Page 979 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 4. Stop engine and check fluid level. Fluid should be between min. and max. lines on dip- stick. 27661 Typical Hurth Transmission Shown Transmission Removal 1. Disconnect wires from neutral safety switch and audio warning temperature switch. 2.
  • Page 980 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 3. Remove bolts and locknuts and remove transmission. 72720 Bolts (2), One On Each Side Locknuts (4), Two On Each Side Transmission Installation 1. Coat splines on input shaft with Quicksilver Engine Coupler Spline Grease. 71044 Input Shaft Index...
  • Page 981 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 2. Install transmission on flywheel housing and secure with hardware shown. Torque fas- teners to 50 lb. ft. (68 N·m). 72720 Bolts (2), One On Each Side Locknuts (4), Two On Each Side 3.
  • Page 982 HURTH V-DRIVE TRANSMSSION SERVICE MANUAL NUMBER 23 4. Connect wires to neutral safety switch and to audio warning temperature switch. Coat connections on neutral safety switch with Quicksilver Liquid Neoprene. 50686 Neutral Safety Switch Audio Warning Temperature Switch Functional Tests 1.
  • Page 983 HURTH V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Shift Lever Motor Speed RPM Duration Minutes Tests Position 800-1000 Neutral 600-800 (Idling A B Position –– 1 2 3 Speed) Repeatedly 1500-2500 B Position 1 2 4 600-800 (Idling A B Position ––...
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  • Page 985 WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 DRIVES Section 8E - Walter V-Drive Transmission Table of Contents Specifications ......8E-2 Changing Transmission Fluid .

  • Page 986: Specifications

    WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Specifications Transmission Fluid Capacities MODEL U.S. QTS. (LITERS) Walter RV26D V-Drive 1 Quart (.9 Liter) Use dipstick to determine fluid exact level. Warm Fluid Level Check: The transmission should be at operating temperature [190 F (90 C)] maximum to receive an accurate oil level reading.

  • Page 987: Changing Transmission Fluid

    WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Changing Transmission Fluid Draining Transmission 1. Remove the magnetic drain plug. 2. Disconnect oil hose from strainer fitting on bottom cover. 3. Remove oil strainer fitting from bottom cover. Do not remove elbow fitting from oil strainer fitting.

  • Page 988: Removal

    WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Filling Transmission 1. Remove dipstick from top cover. Fill transmission with fluid, through dipstick hole, to bring up to full mark. 75192 Dipstick IMPORTANT: To accurately check fluid level, run engine for 2 minutes immediately prior to checking level.
  • Page 989 WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 5. Disconnect the wires to the oil pressure switch. 75647 Oil Pressure Switch Water Hoses 6. Remove nuts from the adapter housing. 75191 Nuts (6) 7. Remove the Walter V-Drive transmission from the adapter housing. Index 90-861326--1 MARCH 1999 Page 8E-5...

  • Page 990: Installation

    WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 Installation 1. Slide the over the studs in the adapter housing. The flange may have to be rotated to align the splines on the adapter flange on the Walter V-Drive transmission and the out- drive flange on the in-line transmission.
  • Page 991 WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 5. Start engine and run it until it reaches normal operating temperature. Stop engine, remove dipstick and check fluid level. 75192 Dipstick 6. Connect the propshaft coupling to the output shaft flange of the transmission. Torque screws and nuts to 50 lb.
  • Page 992 WALTER V-DRIVE TRANSMISSION SERVICE MANUAL NUMBER 23 THIS PAGE IS INTENTIONALLY BLANK Index Page 8E-8 90-861326--1 MARCH 1999 Downloaded from https://needmanual.com/...
  • Page 993 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 23 DRIVES Section 8F - Drive Shaft / Propeller Shaft Models Table of Contents Torque Specifications ....8F-2 Installation .

  • Page 994: Tools

    DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 23 Torque Specifications Fastener Location Lb. Ft. N·m Drive Shaft To Bearing Support Flange (MCM Models) Drive Shaft To Output Shaft (MCM Models) Propeller Shaft Coupling To Transmission Coupling (MIE Models) Flywheel Housing To Block (MCM Models) Output Shaft Housing To Flywheel Housing (MCM Models) Engine Coupling...

  • Page 995: Flywheel Housing/Output Shaft Housing Repair (Mcm Sterndrive Models)

    DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 23 Flywheel Housing/Output Shaft Housing Repair (MCM Sterndrive Models) NOTICE to INSTALLER The following repair procedure requires removal of the drive shaft. In most cases, because of engine compartment space limitations, the engine also must be removed.
  • Page 996 DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 23 10. Install drive shaft and check alignment. (Refer to SECTION 2B for engine and drive shaft alignment if engine was removed.) 11. Using Quicksilver U-Joint and Gimbal Bearing Grease, grease ball bearing through grease fitting.

  • Page 997: Drive Shaft Repair (Mcm Sterndrive Models)

    DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 23 Drive Shaft Repair (MCM Sterndrive Models) Removal IMPORTANT: It is not necessary to remove the engine to service the drive shaft. 1. Remove top and bottom drive shaft shields around transom end and engine end of drive shaft.

  • Page 998: Repair

    DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 23 3. Remove drive shaft fasteners and drive shaft. 70237 Engine End Shown (Transom End Similar) Output Shaft Flange Drive Shaft Bolt With Nut (4 Total) Repair CAUTION Be sure U-joint locking rings are seated properly after replacing U-joints. 1.

  • Page 999: Replacement Drive Shafts

    Flange Universal Joint Sound Deadener (Cardboard Tube) The complete drive shaft can be ordered from Mercury Marine. Drive Shafts Modified to Shorter Lengths The complete modified (shortened) drive shaft has to be ordered from the boat manufacturer that installed the MerCruiser Power Package.

  • Page 1000: Installation

    DRIVE SHAFT / PROPELLER SHAFT MODELS SERVICE MANUAL NUMBER 23 Installation IMPORTANT: The following instructions are to be used if ONLY the drive shaft was removed for service. Refer to appropriate sections for installation of other compo- nents which require special alignment. 1.

This manual is also suitable for:

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