Isuzu NHR 4J Series Workshop Manual
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Isuzu NHR 4J Series Workshop Manual

Isuzu NHR 4J Series Workshop Manual

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Table of Contents

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WORKSHOP MANUAL
NHR • NKR • NPR
ENGINE
4J SERIES
SECTION 6

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Summary of Contents for Isuzu NHR 4J Series

  • Page 1 WORKSHOP MANUAL NHR • NKR • NPR ENGINE 4J SERIES SECTION 6...
  • Page 2 MEMO .................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
  • Page 3 NOTICE Before using this Workshop Manual to assist you in performing vehicle service and maintenance operations, it is recommended that carefully read thoroughly understand information contained in Section 0A under the headings “GENERAL REPAIR INSTRUCTIONS” and “HOW TO USE THIS MANUAL”.

  • Page 4: Table Of Contents

    THIS MANUAL INCLUDES THE FOLLOWING SECTIONS: SECTION NO. CONTENTS Service Information Engine Mechanical 4JB1/4JB1T/4JB1-TC/4JG2 Engine Engine Cooling Fuel System Engine Electrical Exhaust Gas Recirculation (EGR) System Exhaust Turbocharger...

  • Page 5: Service Information

    HOME SERVICE INFORMATION 00 – 1 SECTION 00 SERVICE INFORMATION CONTENTS PAGE Troubleshooting ......................00 - 2 Main Data and Specifications ..................00 - 30 Service Standard ......................00 - 34 Servicing........................... 00 - 38 Fixing Torque ........................00 - 51 Special Tools........................

  • Page 6: Troubleshooting

    00 – 2 SERVICE INFORMATION TROUBLESHOOTING CONTENTS PAGE Hard Starting ........................00 - 3 Starter Inoperative....................... 00 - 3 Starter Motor Operates but Engine Does Not Turn Over ......... 00 - 3 Engine Turns Over but Does Not Start ..............00 - 4 Quick-on Start System ....................

  • Page 7: Hard Starting

    SERVICE INFORMATION 00 – 3 1. HARD STARTING 1. STARTER INOPERATIVE Checkpoint Possible cause Correction Battery Loose battery cable terminal poor Clean and/or retighten the battery connections due to rusting cable terminal Battery discharged or weak Recharge or replace the battery Fan belt loose or broken Adjust or replace the fan belt Fusible link...

  • Page 8: Engine Turns Over But Does Not Start

    00 – 4 SERVICE INFORMATION 3. ENGINE TURNS OVER BUT DOES NOT START Checkpoint Possible cause Correction Engine stop Defective fuel cut solenoid valve Replace the fuel cut solenoid valve mechanism FUEL IS NOT BEING DELIVERED TO THE INJECTION PUMP Fuel Fuel tank is empty Fill the fuel tank...

  • Page 9: Quick-On Start System

    SERVICE INFORMATION 00 – 5 4. QUICK-ON START SYSTEM PREPARATION 1 Disconnect the thermoswitch connector. 2. Determine whether or not the glow plugs are receiving power. a) Make sure that the starter switch is “OFF”. b) Connect a voltmeter between one of the glow plugs and the cylinder wall. c) Move the starter switch to the “ON”...

  • Page 10: Unstable Idling

    00 – 6 SERVICE INFORMATION GLOW PLUGS ARE NOT RECEIVING POWER (Cont’d) Checkpoint Possible cause Correction Glow plug indicator Defective glow plug relay Replace the glow plug relay light turns on for 3.5 The glow plug relay does not turn on after the seconds starter switch is moved from the “OFF”...

  • Page 11: Insufficient Power

    SERVICE INFORMATION 00 – 7 Checkpoint Possible cause Correction Injection pump Injection timing improperly adjusted Adjust the injection timing (Cont’d) Insufficient injection volume Adjust the injection volume Defective idle spring Replace the idle spring Defective governor lever operation Repair or replace the governor lever Regulator valve improperly adjustment Adjust or replace the regulator valve Broken plunger spring...
  • Page 12 00 – 8 SERVICE INFORMATION Checkpoint Possible cause Correction Injection pump Defective regulating valve Repair or replace the regulating valve Defective delivery valve Replace the delivery valve Defective timer Repair or replace the timer Worn cam disc Replace the cam disc Improper control lever operation Adjust or replace the control lever Defective injection timing...

  • Page 13: Excessive Fuel Consumption

    SERVICE INFORMATION 00 – 9 4. EXCESSIVE FUEL CONSUMPTION Checkpoint Possible cause Correction Fuel system Fuel leakage Repair or replace the fuel system related parts Air cleaner Clogged air cleaner element Clean or replace the air cleaner element Idling speed Poorly adjusted idling speed Adjust the idling speed Injection nozzle...

  • Page 14: White Exhaust Smoke

    00 – 10 SERVICE INFORMATION 6. OVERHEATING Checkpoint Possible cause Correction Cooling water Insufficient cooling water Replenish the cooling water Fan clutch Oil leakage from the fan clutch Replace the fan clutch Fan belt Fan belt loose or cracked causing slippage Replace the fan belt Radiator Defective radiator cap or clogged radiator...

  • Page 15: Dark Exhaust Smoke

    SERVICE INFORMATION 00 – 11 8. DARK EXHAUST SMOKE Checkpoint Possible cause Correction Air cleaner Clogged air cleaner element Clean or replace the air cleaner element Injection nozzle Injection nozzle injection starting pressure Adjust or replace the injection nozzle too low Improper spray condition Fuel injection timing Fuel injection timing improperly adjusted...

  • Page 16: Abnormal Engine Noise

    00 – 12 SERVICE INFORMATION 10. ABNORMAL ENGINE NOISE 1. ENGINE KNOCKING Check to see that the engine has been thoroughly warmed up before beginning the troubleshooting procedure. Checkpoint Possible cause Correction Fuel Fuel unsuitable Replace the fuel Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing Injection nozzle...

  • Page 17: Slapping Noise

    SERVICE INFORMATION 00 – 13 4. SLAPPING NOISE Checkpoint Possible cause Correction Valve clearance Valve clearance improperly adjusted Adjust the valve clearance Rocker arm Damaged rocker arm Replace the rocker arm Flywheel Loose flywheel bolts Retighten the flywheel bolts Crankshaft and thrust Worn or damaged crankshaft and/or thrust Replace the crankshaft and/or the bearings...

  • Page 18: Engine Cooling Trouble

    00 – 14 SERVICE INFORMATION 11. ENGINE COOLING TROUBLE Checkpoint Possible cause Correction Engine overheating Low coolant level Replenish Thermo unit faulty Replace Faulty thermostat Replace Faulty coolant unit Repair or replace Clogged radiator Clean or replace Faulty radiator cap Replace Low engine oil level or use of improper Replenish or change oil...

  • Page 19: Engine Electrical Part Trouble

    SERVICE INFORMATION 00 – 15 12. ENGINE ELECTRICAL PART TROUBLE STARTER DOES NOT RUN CHECK BATTERY CHARGING FAILURE OR LIFE BATTERY IS NORMAL CHECK BATTERY CHECK TERMINAL CONNECTION CONNECTION FAILURE TERMINAL CONNECTION IS NORMAL CHECK STARTER OR STARTER SWITCH CLEAN BATTERY TERMINALS, AND RECONNECT FAILURE REPAIR OR REPLACE TURN ON HEAD LAMP AND STARTER SWITCH...
  • Page 20 00 – 16 SERVICE INFORMATION FAULTY MESHING OF PINION AND RING GEAR CHECK IF BATTERY VOLTAGE IS PRESENT AT MAGNETIC SWITCH TERMINAL “S” WHEN STARTER SWITCH IS TURNED TO “START (ST)” UNDER THIS CONDITION, CHECK IF VOLTAGE OF CONNECTOR 3BW ON MAGNETIC SWITCH OF RESTART RELAY IS NORMAL EXTREME WEAR OF STARTER SLIDING...
  • Page 21 SERVICE INFORMATION 00 – 17 MAGNETIC SWITCH DOES NOT OPERATE THOUGH STARTER SWITCH IS TURNED TO “START (ST)” CHECK IF VOLTAGE IS PRESENT AT MAGNETIC SWITCH TERMINAL “S” WHEN STARTER SWITCH IS TURNED TO “START (ST)” CHECK GROUND CABLE CHECK IF INDICATOR LAMP ON METER COMES ON NORMALLY REPAIR CHECK CONTINUITY...
  • Page 22 00 – 18 SERVICE INFORMATION PINION MESHES WITH RING GEAR BUT ENGINE DOES NOT RUN CHECK GROUND CABLE REPAIR OR REPLACE GROUND CABLE FAULTY CONNECTION BURNED-OUT DISCONNECTION DISCONNECTION SLIP OF OF BRUSH AND MAGNETIC OR DAMAGE OF OR DAMAGED OF PINION COMMUTATOR STARTER SWITCH...
  • Page 23 SERVICE INFORMATION 00 – 19 STARTER DOES NOT STOP THOUGH STARTER SWITCH IS RETURNED TO “ON” FROM “START” DISCONNECTED STARTER SWITCH WIRING CONNECTOR, AND CHECK STARTER SWITCH OPERATION. BATTERY IGNITION BATTERY ACCESSORIES IGNITION STARTER POSITION LOCK START THERE MUST BE NO CONTINUITY EXCEPT ABOVE LINES. MAGNETIC SWITCH CONTACTS ARE REPLACE STARTER SWITCH FUSED AND NOT MOVED, OR A...
  • Page 24 00 – 20 SERVICE INFORMATION 13. TURBOCHARGER 1) ENGINE HAS LESS THAN NORMAL POWER Checkpoint Trouble Cause Countermeasure Air cleaner Restricted Clean or replace Intake pipe and hose Restricted Clean or replace Compressor/Intake manifold Loose (Leaking) Repair Exhaust manifold/turbine inlet Loose (Leaking) Repair Exhaust piping and silencers...
  • Page 25 SERVICE INFORMATION 00 – 21 Checkpoint Trouble Cause Countermeasure Continued from the previous page Compressor wheel Impact damage Replace Turbine wheel Impact damage Replace Carbon build-up Replace Rotating assembly Dragging or seized Replace...
  • Page 26 00 – 22 SERVICE INFORMATION 2) BLUE OR BLACK SMOKE Checkpoint Trouble Cause Countermeasure Air cleaner or intercooler Restricted Clean, repair, or replace Turbocharger oil seal Leakage Replace Turbocharger oil drain pipe Restricted Repair or replace Air breather Restricted Clean Boost compensator Defective Repair or replace...
  • Page 27 SERVICE INFORMATION 00 – 23 Checkpoint Trouble Cause Countermeasure Continued from the previous page Center housing oil drain passage Restricted Clean or replace...
  • Page 28 00 – 24 SERVICE INFORMATION 3) EXCESSIVE OIL CONSUMPTION Checkpoint Trouble Cause Countermeasure Air breather Restricted Clean Boost compensator Defective Repair or replace (Injection pump) Turbocharger oil seal Leakage Replace Turbocharger oil drain pipe Restricted Clean or replace Turbine wheel Impact damage Replace Compressor wheel...
  • Page 29 SERVICE INFORMATION 00 – 25 Checkpoint Trouble Cause Countermeasure Continued from the previous page Center housing oil drain passage Restricted Clean or replace...
  • Page 30 00 – 26 SERVICE INFORMATION 4) EXCESSIVE TURBOCHARGER NOISE Checkpoint Trouble Cause Countermeasure Intake and exhaust Restricted Repair system joints Intake and exhaust system Damaged Replace gaskets Turbocharger rotating parts Rough rotation Replace Compressor wheel Rubbing against housing Repair or replace Damaged Replace Turbine wheel...
  • Page 31 SERVICE INFORMATION 00 – 27 Checkpoint Trouble Cause Countermeasure Continued from the previous page Oil level Too low Correct Contaminated Replace oil Turbocharger oil feed pipe Restricted Repair or replace Turbine housing Carbon deposits Clean Compressor housing Dirty Clean Turbine shaft bearings Worn Replace...
  • Page 32 00 – 28 SERVICE INFORMATION 5) EXCESSIVE ROTATING PART WEAR Checkpoint Trouble Cause Countermeasure Engine oil Contaminated Change Wrong grade or type Change Turbocharger oil feed pipe Restricted Clean or replace Turbocharger oil seal Defective Replace Center housing oil Restricted Clean or replace drain passage Turbine shaft...

  • Page 33: Lubrication Chart

    SERVICE INFORMATION 00 – 29 LUBRICATION CHART 4JB1, 4JB1TC, 4JG2, Oil Filter & Oil Cooler kPa (Kg/cm /psi) Oil filter relief valve opening pressure 559 - 0618 (5.7 - 6.3/81 - 90) " Oil cooler safety valve opening pressure 314 - 373 (3.2 - 3.8/46 - 54) Oil filter safety valve opening pressure 78 - 118 (0.8 - 1.2/11 - 19) Oil pressure switch opening pressure...
  • Page 34 00 – 30 SERVICE INFORMATION MAIN DATA AND SPECIFICATIONS MAIN DATA AND SPECIFICATIONS Engine Model 4JB1 / 4JB1T / 4JB1TC 4JG2 (G. EXP & EC) Item Engine type Four-cycle, overhead valve, water cooled Combustion chamber type Direct injection In direct injection Cylinder liner type Dry type, chrome plated, stainless steel tube Timing train system...
  • Page 35 SERVICE INFORMATION 00 – 31 Engine Model 4JB1 / 4JB1T / 4JB1TC 4JG2 (G. EXP & EC) Item Lubricating system Lubrication method Pressurized circulation Specified engine oil (API grade) CC (4JB1) CD (4JB1T/4JB1TC) Oil pump type Gear Oil filter type Disposable cartridge (Spin-on) Paper element Oil capacity (Including oil filter) lit (US/UK gal)

  • Page 36: Engine Cooling

    00 – 32 SERVICE INFORMATION Engine Cooling Cooling system Coolant forced circulation Radiator (2 tube in row) Tube type Corrugated Heat radiation capacity kcal/h 71400 Heat radiation area 11.78 (126.8) Front area 0.216 (2.325) Dry weight N (Kg/lb) 105 (10.7/23.6) Radiator cap Valve opening pressure kPa (Kg/cm...

  • Page 37: Charging System

    SERVICE INFORMATION 00 – 33 Charging System Manufacturer HITACHI LR150-449B DENSO Rated voltage Rated output Rotating direction Clockwise Clockwise (As viewed from pulley) Pulley effective diameter mm (in) 80 (3.15) 82 (3.23) Weight (with pump) kg (lb) 6.0 (13.27) 6.7 (14.77) 4JB1TC for G.E 4JB1TC for Thailand 4JB1TC for EC...

  • Page 38: Service Standard

    00 – 34 SERVICE INFORMATION SERVICE STANDARD Engine Mechanical mm (in) Service standard Service limit Parts Items Remarks 4JB1 / 4JB1T / 4JB1 / 4JB1T / 4JG2 4JG2 4JB1TC 4JB1TC Cylinder Cylinder head deck, and Head exhaust manifold mating 0.05 (0.002) or less 0.2 (0.0079) surface for flatness Cannot be...
  • Page 39 SERVICE INFORMATION 00 – 35 mm (in) Service standard Service limit Parts Items Remarks 4JB1 / 4JB1T / 4JB1 / 4JB1T / 4JG2 4JG2 4JB1TC 4JB1TC Push rod Curvature 0.4 (0.0157) or less Camshaft End play 0.08 (0.0031) 0.2 (0.0079) Cam lobe height 42.02 (1.6543) 41.65 (1.6397)
  • Page 40 00 – 36 SERVICE INFORMATION mm (in) Service standard Service limit Parts Items Remarks 4JB1 / 4JB1T / 4JB1 / 4JB1T / 4JG2 4JG2 4JB1TC 4JB1TC Piston, Piston diameter 95.365 - 95.404 92.985 - 93.024 Piston (3.7545-3.9039) (3.6600-3.6623) pin, Piston Clearance 0.047 - 0.065 0.025 - 0.045 Piston...
  • Page 41 SERVICE INFORMATION 00 – 37 mm (in) Service standard Service limit Parts Items Remarks 4JB1 / 4JB1T / 4JB1 / 4JB1T / 4JG2 4JG2 4JB1TC 4JB1TC Cylinder Warpage 0.20 (0.0079) Block (Upper surface of the cylinder block) Cylinder bore diameter 97.000 - 97.040 95.011 - 95.040 (3.8189 - (3.7406 -...

  • Page 42: Model Identification

    Do not bang the element against another object in an attempt to clean it. Damage to the element will result. Carbon and Dust Fouled Element 1. Prepare a cleaning solution of Isuzu Genuine Element Cleaner (Donaldson D1400) diluted with water. 2. Submerge the element in the solution for twenty minutes.

  • Page 43: Lubricating System

    SERVICE INFORMATION 00 – 39 3. Remove the element from the solution and rinse it well with running water. Water pressure must not exceed 274 kPa (2.8 kg/cm /40Psi) 0039-1.tif 4. Dry the element in a well ventilated area. An electric fan will hasten drying. NOTE: Do not use compressed air or an open flame to dry the element quickly.

  • Page 44: Fuel System

    7. Retighten the bleeder plug. 8. Operate the priming pump several times and check for fuel leakage. NOTE: The use of an ISUZU genuine fuel filter is strongly recommended. 0040-4.tif Fuel Filter Water Draining Procedure The indicator light will come on when the water level in the water separator exceeds the specified level.

  • Page 45: Cooling System

    Also check to see that the fuel filter water indicator light has turned off. If water separator requires frequent draining, have the fuel tank drained for removal of water at your Isuzu Dealer. Air Bleeding 1.
  • Page 46 (ethylene-glycol based). Replace damaged rubber hoses as the engine anti-freeze coolant is liable to leak out even minor cracks. Isuzu recommends to use lsuzu genuine anti-freeze (ethylene-glycol based) or equivalent, for the cooling system and not add any inhibitors or additives.
  • Page 47 SERVICE INFORMATION 00 – 43 needle position of water thermomete, conduct a 5 minutes idling again and stop the engine. 10 When the engine has been cooled, check filler neck for water level and replenish if required. Should extreme shortage of coolant is found, Check the coolant system and reservoir tank hose for leakage.
  • Page 48 00 – 44 SERVICE INFORMATION Drive Belt Adjustment Depress the drive belt mid portion with a 98N (10 kg/22 lb) force. Drive Belt Deflection mm (in) 10 (0.39) Check the drive belt for cracking and other damage. 1. Crankshaft damper pulley 2.
  • Page 49 SERVICE INFORMATION 00 – 45 ENGINE CONTROL Idling Speed Inspection 1. Set the vehicle parking brake and choke the drive wheels. 2. Place the transmission in neutral. 3. Start the engine and allow it to warm up. 4. Disconnect the engine control cable from the control lever.

  • Page 50: Valve Clearance Adjustment

    00 – 46 SERVICE INFORMATION 1. Hold the accelerator pedal pad securely by hand, and give it a full stroke. 2. Adjust the stopper bolt so that the clearance between the pad stopper bolt and the rear side of the pad becomes the specified length.
  • Page 51 SERVICE INFORMATION 00 – 47 Adjust the No. 1 or the No. 4 cylinder valve clearance while their respective cylinders are at TDC on the compression stroke. Valve Clearance (At Cold) mm (in) 0.4 (0.016) 4. Loosen each valve clearance adjusting screw as shown in the illustration.
  • Page 52 00 – 48 SERVICE INFORMATION 7. Rotate the crankshaft to bring the piston in the No. 1 cylinder to a point 30 - 40° BTDC. 8. Set the timing gauge needle to zero. 9. Move the crankshaft pulley slightly in both directions to check that the gauge indication is stable.
  • Page 53 SERVICE INFORMATION 00 – 49 COMPRESSION PRESSURE MEASURE- MENT 1. Start the engine and allow it to idle until the coolant temperature reaches 70 - 80°C (158 - 176°F). 2. Remove the following parts. Glow plugs Fuel cut solenoid connector QOS (Quick-On Start System) fusible link wire at the connector.
  • Page 54 00 – 50 SERVICE INFORMATION QUICK-ON START III SYSTEM (4JG2 only) Quick-On Start System Inspection Procedure 1. Disconnect the thermo-sensor connection on the thermostat outlet pipe. 2. Turn the starter switch to the “ON” position. If the Quick-On Start III System is operating properly, the glow relay will make a clicking sound within seven 0049-1.tif seconds after the starter switch is turned on.
  • Page 55 SERVICE INFORMATION 00 – 51 FIXING TORQUE CYLINDER HEAD COVER, CYLINDER HEAD ROCKER, SHAFT BRAKER N∙m (kg∙m/lb∙ft) 011LX002.tif...
  • Page 56 00 – 52 SERVICE INFORMATION Crankshaft, Bearing Cap, Connecting Rod Bearing Cap, Crankshaft Damper Pulley, Flywheel, Oil Pan N∙m (kg∙m/lb∙ft) 0051-1.tif...
  • Page 57 SERVICE INFORMATION 00 – 53 Timing Pulley Housing, Timing Pulley, Timing Gear, Camshaft Oil Seal Retainer N∙m (kg∙m/lb∙ft) 014LX001.tif...
  • Page 58 00 – 54 SERVICE INFORMATION Cooling System and Lubrication System N∙m (kg∙m/lb∙ft)
  • Page 59 SERVICE INFORMATION 00 – 55 Intake Manifold, Exhaust Manifold, Exhaust Pipe N∙m (kg∙m/lb∙ft) 150LX004.tif...
  • Page 60 00 – 56 SERVICE INFORMATION N∙m (kg∙m/lb∙ft) 036LX003.tif...
  • Page 61 SERVICE INFORMATION 00 – 57 Engine Electricals N∙m (kg∙m/lb∙ft) 0056-1.tif...
  • Page 62 00 – 58 SERVICE INFORMATION Engine Fuel N∙m (kg∙m/lb∙ft) 0057-1.tif...
  • Page 63 SERVICE INFORMATION 00 – 59 Engine Mounting Bracket N∙m (kg∙m/lb∙ft) 0058-1.tif...

  • Page 64: Special Tools

    00 – 60 SERVICE INFORMATION SPECIAL TOOLS ILLUSTRATION TOOL NO. TOOL NAME 5-8840-2035-0 Crank Timing Pulley (4JG2 Belt Drive only) 5-8840-0200-0 Oil Filter Wrench (89.0 mm/3.5 in) 5-8840-0202-0 Oil Filter Wrench (106.0 mm/4.2 in) 5-8840-2209-0 Oil Filter Wrench (100.6 mm/4.0 in) 9-8523-1423-0 (J-29760) Valve Spring Compressor 5-8840-2033-0...
  • Page 65 SERVICE INFORMATION 00 – 61 SPECIAL TOOLS (CONT.1) ILLUSTRATION TOOL NO. TOOL NAME 5-8840-2675-0 Compression gauge 5-8531-7001-0 Gauge Adapter 5-8531-7002-0 Gauge Adapter 5-8840-0145-0 Measuring Device Crankshaft Timing Pulley Installer 5-8522-0024-0 (4JG2 Belt Drive only) 5-8840-0266-0 Angle Gauge 5-8840-9016-0 Injection Nozzle Tester 5-8840-2034-0 Nozzle Holder Remover (4JB1 only) 5-8840-2038-0...
  • Page 66 00 – 62 SERVICE INFORMATION SPECIAL TOOLS (CONT.2) LLUSTRATION TOOL NO. TOOL NAME 5-8840-0259-0 Nozzle Holder Wrench (4JG2 only) 5-8840-0253-0 (J-22700) Fuel Filter Wrench 5-8840-2362-0 Front Oil Seal Remover (4JG2, Belt Drive only) 5-8840-2361-0 Front Oil Seal Installer (4JG2, Belt Drive only) 5-8840-2360-0 Rear Oil Seal Remover 5-8840-2359-0...
  • Page 67 SERVICE INFORMATION 00 – 63 MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
  • Page 68 HOME GENERAL ENGINE MECHANICAL 6A – 1 SECTION 6A GENERAL ENGINE MECHANICAL CONTENTS PAGE Cylinder Head......................... 6A - Valve Spring, Valve Guide Oil Seal, Valve Guide, Push Rod ........6A - 10 Camshaft, Tappet......................6A - 17 Rocker Arm Assembly....................6A - 24 Oil Pump .........................

  • Page 69: Cylinder Head

    6A – 2 GENERAL ENGINE MECHANICAL CYLINDER HEAD Disassembly steps 1. Thermostat housing Assembly 2. Injection nozzle holder (4JG2) 2a. Injection nozzle holder (4JB1 (4JB1) 4JB1TC) 3. Glow plug and plug connector (4JG2) 3a. Glow plug and plug connector (4JB1 4JB1TC) 4.

  • Page 70: Inspection And Repair

    GENERAL ENGINE MECHANICAL 6A – 3 2) Use the nozzle holder remover and the sliding hammer to remove the nozzle holder together with the holder bracket. Nozzle Holder Remover: 5-8840-2034-0 Sliding Hammer: 5-8840-0019-0 6A-3-1.tif 3. Glow Plug and Glow Plug Connector (4JG2) 3a.
  • Page 71 6A – 4 GENERAL ENGINE MECHANICAL CAUTION: Do not attempt to weld the cylinder head. Replace it. 4. Cylinder head deck, intake and exhaust manifold mating surfaces for flatness. These surfaces may be re-conditioned by milling (except cylinder head lower face). If the surfaces are “out of flat”...
  • Page 72 GENERAL ENGINE MECHANICAL 6A – 5 Hot plug removal (4JG2 only) 1. Insert a 3.0 - 5.0 (0.12 - 0.20.) diameter bar into the nozzle holder fitting hole unit it makes contact with the hot plug. 2. Lightly tap the bar with a hammer to drive the hot plug free.
  • Page 73 6A – 6 GENERAL ENGINE MECHANICAL CAUTION: Do not apply pressure greater than that specified. Damage to the cylinder head will result. 6. Use a surface grinder to grind off any hot plug surface protuberances. The hot plug surfaces must be perfectly flush with the cylinder head.
  • Page 74 GENERAL ENGINE MECHANICAL 6A – 7 NOTE: After being pressed into the cylinder head, the hot plugs were provided with surface grinding. Accordingly, their dimensions are different individually among them, and take care not confuse the order of the cylinders. When replacing the hot plug with new one: When assembling a new hot plug, set the knock ball in the positioning groove on the cylinder side and hit it lightly with...
  • Page 75 6A – 8 GENERAL ENGINE MECHANICAL 3) Spring lower seat 4) Valve stem oil seal • Install a new oil controller in the valve. • Guide using special tool Oil seal installer: 5-8840-2003-0 5) Valve • Apply engine oil to the outside of the valve stem before installing it.
  • Page 76 GENERAL ENGINE MECHANICAL 6A – 9 2a. Injection Nozzle Holder (4JB1/4JB1T/4JB1TC only) " 1) Install the injection nozzle gasket and the O-ring to the injection nozzle holder Be sure that the O-ring fits snugly in the injection nozzle groove. 2) Apply engine oil to the cylinder head nozzle holder hole.
  • Page 77 6A – 10 GENERAL ENGINE MECHANICAL VALVE SPRING, VALVE GUIDE OIL SEAL, VALVE GUIDE, PUSH ROD 6A-10-1.tif DISASSEMBLY 1. Rocker Arm Assembly 2. Split Collar Using special Tool, compress valve spring Valve spring compressor: 9-8523-1423-0 (J-29760) 3. Valve Spring 4. Valve 5.
  • Page 78 GENERAL ENGINE MECHANICAL 6A – 11 INSPECTION AND REPAIR Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection. Valve spring CAUTION: Visually inspect the valve springs and replace them if damage or abnormal wear is evident. 1.
  • Page 79 6A – 12 GENERAL ENGINE MECHANICAL 1. Valve Guide Clearance • Measure the valve stem diameter with a micrometer. If the valve stem diameter is less than the specified limit, the valve and the valve guide must be replaced as a set. mm (in) Standard Limit...
  • Page 80 GENERAL ENGINE MECHANICAL 6A – 13 Valve Guide Replacement 1. Using special tool, drive out the valve guide from the combustion chamber side. Valve guide replacer: 9-8523-1212-0 6A-13-1.tif 2. Apply engine oil to the outside of the valve guide. Using special tool, drive in a new valve guide from cylinder head upper face side, and check the valve guide height.
  • Page 81 6A – 14 GENERAL ENGINE MECHANICAL Valve depression 1. Install the valve (1) to the cylinder head (2). 2. Use a depth gauge or a straight edge with steel rule to measure the valve depression from the cylinder head lower surface. If the measured value exceeds the specified limit, the valve seat insert must be replaced.
  • Page 82 GENERAL ENGINE MECHANICAL 6A – 15 NOTE: Do not apply an excessive amount of pressure with the bench press. Damage to the valve seat insert will result. Valve Seat Insert Correction 1. Remove the carbon from the valve seat insert surface. 2.
  • Page 83 6A – 16 GENERAL ENGINE MECHANICAL REASSEMBLY 6. Valve Guide • Apply engine oil to the outside of the valve guide. Using special tool, drive in a new valve guide from the rocker arm shaft side. Valve guide replacer: 9-8523-1212-0 5.
  • Page 84 GENERAL ENGINE MECHANICAL 6A – 17 CAMSHAFT, TAPPET 6A-17-1.tif DISASSEMBLY 1. Cylinder Head Assembly 2. Flywheel 3. Cylinder Block Rear Plate 4. Oil Pan Assembly 5. Oil Pump Assembly 6. Camshaft Timing Gear (Gear Drive Model) • Remove the camshaft timing gear bolt from the camshaft.
  • Page 85 6A – 18 GENERAL ENGINE MECHANICAL 6a. Camshaft Timing Pulley (Belt Drive Model) " • Use the timing pulley puller to remove the pulley. Timing Pulley Puller: 5-8840-0086-0 • Remove the stopper bolt. 7. Camshaft Thrust Plate (Gear Drive Model) 7a.
  • Page 86 GENERAL ENGINE MECHANICAL 6A – 19 4. Camshaft Run-Out • Mount the camshaft on V-blocks. • Measure the run-out with a dial indicator. If the measured value exceeds the specified limit, the camshaft must be replaced. Run-Out mm (in) Standard Limit 0.02 (0.008) or less 0.10 (0.0039)
  • Page 87 6A – 20 GENERAL ENGINE MECHANICAL TAPPET Visually inspect the tappet camshaft contact surfaces for pitting, cracking, and other abnormal conditions. The tappet must be replaced if any of these conditions are present. Refer to the illustration at the left. Normal contact "...
  • Page 88 GENERAL ENGINE MECHANICAL 6A – 21 8. Camshaft 1) Apply a coat of engine oil to the camshaft and the camshaft bearings. 2) Install the camshaft to the cylinder body. Take care not damage the camshaft bearings. 6A-21-1.tif 7a. Camshaft Timing Pulley Center (Belt Drive Model) •...
  • Page 89 6A – 22 GENERAL ENGINE MECHANICAL 6. Camshaft Timing Gear (Gear Drive Model) 1) Install the camshaft timing gear to the camshaft. The timing gear mark (“Y-Y”) must be facing outward. 2) Tighten the timing gear to the specified torque Timing Gear Bolt Torque N∙m (kg∙m/lb∙ft) 64 (6.5/47)
  • Page 90 GENERAL ENGINE MECHANICAL 6A – 23 When replacing the hot plug with new one: When assembling a new hot plug, set the knock ball in the positioning groove on the cylinder side and hit it lightly with a plastic hammer until the hot plug is set in stably. With patch attached to the hot plug to prevent it from being damaged, press it in with a force of 4.5 ~ 5.5 ton applied.

  • Page 91: Rocker Arm Assembly

    6A – 24 GENERAL ENGINE MECHANICAL ROCKER ARM ASSEMBLY 6A-24-1.tif DISASSEMBLY 1. Rocker Arm Shaft Assembly 2. Rocker Arm Shaft Snap Ring 3. Rocker Arm 4. Rocker Arm Shaft Bracket 5. Rocker Arm 6. Rocker Arm Shaft Spring 7. Rocker Arm Shaft INSPECTION AND REPAIR Make the necessary adjustment, repairs, and part replacements if excessive wear or damage is discovered...
  • Page 92 GENERAL ENGINE MECHANICAL 6A – 25 Oil Clearance 1. Use either a vernier caliper or a dial indicator to measure the rocker arm inside diameter. Rocker Arm Inside Diameter mm (in) Standard Limit 19.036 - 19.060 19.100 (0.7519) (0.7494 - 0.7503) 2.
  • Page 93 6A – 26 GENERAL ENGINE MECHANICAL Rocker Arm Shaft Run-Out 1. Place the rocker arm shaft on a V-block. 2. Use a dial indicator to measure the rocker arm shaft central portion run-out. If the run-out is very slight, correct the rocker arm shaft run-out with a bench press.

  • Page 94: Oil Pump

    GENERAL ENGINE MECHANICAL 6A – 27 OIL PUMP Disassembly steps 1. Vacuum pump oil hose 2. Stiffener and space rubber 3. Oil pan Assembly 4. Oil pump Assembly 5. Strainer 6. Pump cover 7. Driven gear 8. Oil pump body 6A-27-1.tif DISASSEMBLY 1.
  • Page 95 6A – 28 GENERAL ENGINE MECHANICAL 4. Oil Pump Assembly 5. Strainer 6. Pump Cover 7. Driven Gear 8. Oil Pump Body INSPECTION AND REPAIR Make the necessary adjustment, repairs, and part replacements if excessive wear or damage is discovered during inspection.
  • Page 96 GENERAL ENGINE MECHANICAL 6A – 29 REASSEMBLY 8. Oil Pump Body 7. Driven Gear Pump Cover 5. Strainer • Install the strainer assembly and tighten the strainer assembly fixing bolts. N∙m (kg∙m/lb∙ft) 16 (1.6/12) 6A-29-1.tif 4. Oil Pump Assembly • Apply molybdenum mixed engine oil to drive gear of camshaft and driven gear of oil pump.
  • Page 97 6A – 30 GENERAL ENGINE MECHANICAL 2. Stiffener & Space Rubber • Install the space rubber. • Install the stiffener tighten to the specified torque. Engine Body Side N∙m (kg∙m/lb∙ft) 37 (3.8/27) Clutch Housing Side N∙m (kg∙m/lb∙ft) 78 (8.0/58) 1. Vacuum Pump Oil Hose •...
  • Page 98 GENERAL ENGINE MECHANICAL 6A – 31 CRANKSHAFT Disassembly steps 1. Cylinder head Assembly and gasket 2. Oil pan Assembly 3. Timing gear 3a. Timing Belt and Pulley 4. Front oil seal 5. Timing gear housing 5a. Timing pulley housing 6. Oil pump Assembly 7.
  • Page 99 6A – 32 GENERAL ENGINE MECHANICAL 5. Timing Gear Housing 5a.Timing Pulley Housing 6. Oil Pump Assembly 7. Piston Cooling Oil Pipe 8. Piston and Connecting Rod 9. Flywheel 10. Cylinder Block Rear Plate 11. Crankshaft Rear Oil Seal (Gear and Belt Drive Model) •...
  • Page 100 GENERAL ENGINE MECHANICAL 6A – 33 2. Main bearing clearance 1) Remove the main bearing caps in the sequence shown in the illustration. Arrange the removed main bearing caps in the cylinder number order. 2) Remove the crankshaft. Remove the main bearings. 3) Clean the upper and lower bearings as well as the crankshaft main journal.
  • Page 101 6A – 34 GENERAL ENGINE MECHANICAL 3. Run-out 1) Carefully set the crankshaft on the V-blocks. Slowly rotate the crankshaft and measure the runout. If the crankshaft runout exceeds the specified limit, the crankshaft must be replaced. Run-Out mm (in) Standard Limit 0.05 (0.0020)
  • Page 102 GENERAL ENGINE MECHANICAL 6A – 35 3. Use a syringe to apply the solution to the surface to be inspected. Hold the surface to be inspected perfectly horizontal to prevent the solution from running. NOTE: Do not allow the solution to come in contact with the oil ports and their surrounding area.
  • Page 103 6A – 36 GENERAL ENGINE MECHANICAL Main Bearing Crankshaft Crankshaft Oil Clearance Bore Diameter mm (in.) Main Journal Diameter mm (in.) Bearing mm (in.) Size Mark Size Mark Inside Diameter Size Mark Outside Diameter 69.927~69.942 0.035~0.061 1 or - Black (2.7530~2.7536) (0.0014~0.0024) 73.987~74.000...
  • Page 104 GENERAL ENGINE MECHANICAL 6A – 37 12. Main Bearing Cap • Apply the recommended liquid gasket or its equivalent to the No. 5 crankshaft bearing cap as shown in the illustration. " • Install the arch gasket to the No. 5 bearing cap. Use your fingers to push the arch gasket into the bearing cap groove.
  • Page 105 6A – 38 GENERAL ENGINE MECHANICAL 11. Crankshaft Rear Oil Seal (Gear and Belt Drive Model) Use the oil seal installer to install the oil seal to the cylinder body. Installer: Rear Oil Seal 5-8840-2359-0 NOTES: Wipe off rust and scraps clean from the press-in portion of the oil seal.
  • Page 106 GENERAL ENGINE MECHANICAL 6A – 39 6. Oil Pump Assembly Above works refer to “PISTON AND CONNECTING ROD” Section in this manual. 5a. Timing Pulley Housing 1) Install the timing pulley housing to the cylinder body. NOTE: Take care not to twist the front oil seal. 2) Tighten the timing pulley housing bolt together with the timing pulley housing gasket to the specified torque.
  • Page 107 6A – 40 GENERAL ENGINE MECHANICAL 4) After pressing in the oil seal, check the measurement of the oil seal. Standard mm (in) 0.6 - 1.2 (0.024 - 0.047) 3a. Timing Belt and Pulley (Belt Drive Model) 7) Camshaft Timing Pulley •...
  • Page 108 GENERAL ENGINE MECHANICAL 6A – 41 6) Timing Belt NOTE: • When the timing belt is removed, be sure to replace it with a new one. • The tension of the timing belt may be affected by the changes in temperature. Be sure to install it while the engine cold.
  • Page 109 6A – 42 GENERAL ENGINE MECHANICAL NOTE: Timing belt tension must be adjusted. Failure to adjust the timing belt tension will result in timing belt damage. Tighten the tension bolt. Rotate the crankshaft 45 degrees counterclockwise. NOTE: Never rotate the crankshaft clockwise when adjusting the timing belt.
  • Page 110 GENERAL ENGINE MECHANICAL 6A – 43 3) Timing Pulley Lower Cover • Apply the recommended liquid gasket or its equivalent to the timing pulley lower cover. • Install the lower cover to the timing pulley housing. • Use the lower cover guide bolts to prevent the liquid gasket from running.
  • Page 111 6A – 44 GENERAL ENGINE MECHANICAL 10) Crankshaft Timing Gear Install the camshaft timing gear to the camshaft. The timing gear mark (“Y – Y”) must be facing outward. " Tighten the timing gear to the specified torque. N∙m (kg∙m/lb∙ft) 64 (6.5/47) 6A-44-1.tif 9) Idle Gear...
  • Page 112 GENERAL ENGINE MECHANICAL 6A – 45 7) Injection Pump " Install the O-ring to the injection pump flange " Install the injection pump to the timing gear case. Align the idler gear “B” “V-V” mark. 6A-44-5.tif Temporarily tighten the six injection pump nuts The injection pump nuts will be finally tightened after the injection pump rear bracket bolts.
  • Page 113 6A – 46 GENERAL ENGINE MECHANICAL 4) Crankshaft Damper Pulley Tighten the crankshaft damper pulley bolt to the specified torque. NOTE: Hold the flywheel ring gear stationary to prevent the crankshaft from turning when tightening the damper pulley. N∙m (kg∙m/lb∙ft) 206 (21/152) 6A-45-5.tif 3) Cooling Fan Assembly...

  • Page 114: Piston And Connecting Rod

    GENERAL ENGINE MECHANICAL 6A – 47 PISTON AND CONNECTING ROD Disassembly steps 1. Cylinder head Assembly 2. Oil pan Assembly 3. Oil pump Assembly 4. Piston cooling oil pipe 5. Connecting rod bearing cap 6. Piston and connecting rod 7. Piston ring 8.
  • Page 115 6A – 48 GENERAL ENGINE MECHANICAL 7. Piston Ring Remove the piston rings with a piston ring expander. Arrange the removed piston rings in the cylinder number order. 6A-48-1.tif 8. Piston Pin Snap Ring • Use a pair of pliers to remove the piston pin snap rings.
  • Page 116 GENERAL ENGINE MECHANICAL 6A – 49 4JB1 / 4JB1T / 4JB1TC mm (in) Size Mark Outside Diameter 92.985 - 92.994 (3.6608 - 3.6612) 92.995 - 93.004 (3.6612 - 3.6616) 93.005 - 93.014 (3.6616 - 3.6620) 93.015 - 93.024 (3.6620 - 3.6624) 4JG2 mm (in) Size Mark...
  • Page 117 6A – 50 GENERAL ENGINE MECHANICAL NOTE: It is most important that the correct piston grade be used. Failure to select the correct piston grade will result in engine failure. Always measure the cylinder bore and select the correct piston grade. Piston rings Any worn or damaged part discovered during engine overhaul must be replaced with a new one.
  • Page 118 GENERAL ENGINE MECHANICAL 6A – 51 4JG2 mm (in) Standard Limit Compression 0.09-0.13 ring (0.0035 - 0.0051) 0.05 - 0.07 0.15 (0.0020 - 0.0028) (0.0059) 0.03-0.07 Oil ring (0.0012-0.0028) Piston pin Visually inspect the piston pin for cracks, flaws, and other damage and replace if necessary.
  • Page 119 6A – 52 GENERAL ENGINE MECHANICAL Bushing replacement Removal: Use a suitable bar and bench press or hammer. Installation: Use a suitable bar and bench press. NOTE: Align the bushing with the connecting rod oil port. After installing a new bushing, finish the bushing bore with a pin hole grinder.
  • Page 120 GENERAL ENGINE MECHANICAL 6A – 53 5) Tighten the cap nuts in 2 steps, using angular tightening method as shown in the following specifications. (4JG2) 4JG2 N∙m (kg∙m/lb∙ft) 1st Steps 2nd Step 29 (3.0/22) 45° - 75° 4JA1, 4JB1, 4JB1TC N∙m (kg∙m/lb∙ft) 83 (8.5/61) NOTE:...
  • Page 121 6A – 54 GENERAL ENGINE MECHANICAL • Attach the piston to the connecting rod with the piston front mark and the connecting rod ISUZU mark on the same side. 6A-54-1.tif 7. Piston Ring • Install the piston rings with the piston ring expander.
  • Page 122 GENERAL ENGINE MECHANICAL 6A – 55 6. Piston and Connecting Rod • Apply engine oil to the cylinder bores, the connecting rod bearings and the crankshaft pins. • Check to see that the piston ring end gaps are correctly positioned. •...

  • Page 123: Cylinder Block

    6A – 56 GENERAL ENGINE MECHANICAL CYLINDER BLOCK Disassembly steps 1. Cylinder head Assembly and gasket 2. Oil pan Assembly 3. Timing gear 3a. Timing belt and pulley 4. Front oil seal 5. Timing gear housing 5a. Timing pulley housing 6.
  • Page 124 GENERAL ENGINE MECHANICAL 6A – 57 7. Piston Cooling Oil Pipe 8. Piston and Connecting Rod 9. Flywheel 10. Cylinder Block Rear Plate 11. Crankshaft Rear Oil Seal 12. Main Bearing Cap 13. Crankshaft 14. Camshaft 15. Tappet 16. Cylinder Block INSPECTION AND REPAIR Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered...
  • Page 125 6A – 58 GENERAL ENGINE MECHANICAL " 5. Use a straight edge and a feeler gauge measure the four sides and the two diagonals of the cylinder body upper face. If the measured values exceeds the limit, the cylinder body must be replaced. 6A-58-1.tif Cylinder Liner Bore Measurement Use a cylinder indicator to measure the cylinder liner bore...
  • Page 126 GENERAL ENGINE MECHANICAL 6A – 59 Cylinder Body Bore Measurement 1) Take measurements at measuring point (A) across " " positions , and Measuring Point (A) 98mm (3.86 in). 2) Calculate the average value of the four measurements to determine the correct cylinder grade. 3) Consult the following table with the resultant diameter for the correct liner application.
  • Page 127 6A – 60 GENERAL ENGINE MECHANICAL 4JG2 mm (in) Liner Liner Cylinder bore Liner outside outside bore Service liner bore measurement diameter average diameter Grade Grade 95.435 (3.7573) - 95.450 (3.7579) 97.001 - 97.010 97.011 - 97.020 (3.8189 - 3.8193) (3.8193 - 3.8197) 95.451 (3.7579) - 95.466 (3.7585) 95.435 (3.7573) - 95.450 (3.7579)
  • Page 128 GENERAL ENGINE MECHANICAL 6A – 61 4) Set the cylinder liner installer 3 to the top of the cylinder liner. Position the cylinder body so that the installer center is directly beneath the bench press shaft center 4. Cylinder Liner Installer: 5-8840-2313-0 (4JG2) : 5-8840-2040-0 (4JB1/4JB1T/ 4JB1TC) NOTE:...
  • Page 129 4) Install the piston to the connecting rod. The piston head front mark and the connecting rod " “ISUZU” casting mark must be facing the same direction. 6A-62-2.tif 5) Apply a coat of engine oil to the piston pin and the piston pin hole.
  • Page 130 GENERAL ENGINE MECHANICAL 6A – 63 7) Install the piston rings with the piston ring expander. The compression ring must be set with the 1N, 2N mark (4JG2) facing up. Discrimination mark is painted as shown in the illustration. 6A-63-1.tif 8) Use a piston ring replacer to install the three piston rings.
  • Page 131 6A – 64 GENERAL ENGINE MECHANICAL 12) Carefully wipe any oil or other foreign material from connect rod bearing back face and the connecting rod bearing fitting surface. 13) Apply a coat of engine oil to the upper bearing surfaces. Apply a coat of engine oil to the cylinder wall.
  • Page 132 GENERAL ENGINE MECHANICAL 6A – 65 7. Piston Cooling Oil Pipe 1) Fix the oil jet pipes with knock pins on the cylinder block. 2) Install the oil pipe for piston cooling in the cylinder " block, tightening a relief valve and four joint bolts to the specified torque.
  • Page 133 6A – 66 GENERAL ENGINE MECHANICAL 2. Oil Pan Assembly Above works refer to “OIL PUMP” Section in this manual. 1. Cylinder Head Assembly and Gasket Cylinder head gasket is determined by the piston head projection from the cylinder body upper surface, in order to improve engine performance.
  • Page 134 GENERAL ENGINE MECHANICAL 6A – 67 4JG2 Cylinder Head Gasket Thickness mm (in) Grade Average Piston Gasket mark projection thickness 0. 658-0.713 1.60 (0.0259-0.0281) (0.0630) 0.713-0.759 1.65 (0.0281-0.0299) (0.0650) 0.759-0.814 1.70 (0.0299-0.0320) (0.0670) 6A-67-1.tif NOTE: The difference between the highest measured piston head projection and the lowest measured piston head projection must not exceed 1.0mm (0.039 in).
  • Page 135 6A – 68 GENERAL ENGINE MECHANICAL # Tighten the rocker arm shaft bracket bolts to the specified torque in the numerical order shown in the illustration. Rocker Arm Shaft Bracket Bolt Torque N∙m (kg∙m/lb∙ft) 54 (5.5/40) • Valve clearance adjustment. 6A-68-1.tif...
  • Page 136 HOME 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 1 SECTION 6A1 4JB1/4JB1T/4JB1TC/4JG2-ENGINE CONTENTS PAGE General Description....................6A1- Engine Mount (RH)...................... 6A1- Engine Mount (LH) ...................... 6A1- Inlet Manifold....................... 6A1- Exhaust Manifold ......................6A1- 10 Oil Cooler........................6A1- 12 Oil Filter Cartridge ...................... 6A1- 14 Cylinder Head Cover....................

  • Page 137: General Description

    6A1 – 2 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE GENERAL DESCRIPTION 6A1-2-1.tif 4JB1-TC F06LX002.tif F06LX005.tif...
  • Page 138 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 3 The 4JB1 Model engine employs a square troidal type Take care not to damage the oiling jet when removing combustion chamber provided with a fence around it. or installing the piston and the connecting assembly. These designs employed allow a superior fuel The 4JG2 engine use a single spring pintle type economy over a wide range of driving conditions.
  • Page 139 6A1 – 4 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE ENGINE MOUNT (RH) Rigid sus 6A1-4-1.tif REMOVAL Preparation: • Disconnect battery ground cable. 1. Fan Shroud • Remove reservoir tank hose and fan shroud. 2. Fan Belt • Remove adjust plate lock bolt. • Loosen generator fixing bolt then remove fan belt.
  • Page 140 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 5 • Separate the generator from the engine. • Remove the support rubber nut from engine foot side. • Remove the support rubber while raising the engine. 6A1-5-1.tif INSTALLATION 3. Support Rubber • Install the support rubber while raising the engine. •...
  • Page 141 6A1 – 6 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE ENGINE MOUNT (LH) Rigid sus 6A1-6-1.tif REMOVAL Preparation: • Disconnect battery ground cable. 1. Air Intake Duct • Remove the intake duct. 2. Fan Shroud • Remove reservoir tank hose and fan shroud. 6A1-6-2.tif 3.
  • Page 142 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 7 • Remove the support rubber nut from engine foot side. • Remove the support rubber while raising the engine. 6A1-7-1.tif INSTALLATION 3. Support Rubber • Install the support rubber while raising the engine. • Tighten the fixing nuts to the specified torque.
  • Page 143 6A1 – 8 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE INLET MANIFOLD Removal steps 1. Vacuum hose 2. Air intake duct 3. PCV hose 4. Injection pipe 5. Oil level gauge guide tube 6. Oil cooler water pipe (Oil Cooler Model) 7. Inlet manifold Installation steps To install, follow the removal steps in the reverse order.
  • Page 144 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 9 6. Oil Cooler Water Pipe (Oil Cooler Model) • Remove the water pipe bracket bolt. • Remove the inlet manifold fixing nut. 7. Inlet Manifold • Remove the manifold fixing bolt and nut. 6A1-9-1.tif INSTALLATION 7.

  • Page 145: Exhaust Manifold

    6A1 – 10 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE EXHAUST MANIFOLD 6A1-10-1.tif REMOVAL Preparation: • Disconnect battery ground cable. 1. Vacuum Hose (Exhaust Brake Model) • Remove the vacuum actuator hose. 2. Front Exhaust Pipe Nut • Remove the fixing nuts from exhaust manifold side. 3.
  • Page 146 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 11 INSTALLATION 5. Exhaust Manifold • Tighten the fixing nuts and bolts to the specified torque. Manifold Bolt Torque N∙m(kg∙m/lb∙ft) 26 (2.7/20) 4. Heat Protector • Remove the heat protector and tighten to the specified torque.
  • Page 147 6A1 – 12 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE OIL COOLER (Oil Cooler Model) 6A1-12-1.tif REMOVAL Preparation: • Disconnect battery ground cable • Drain coolant • Put rag to beneath side of oil cooler to prevent oil leaking. 1. Water Hose • Disconnect water inlet and outlet hose. 2.
  • Page 148 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 13 INSPECTION Relief Valve 1. Attach an oil pressure gauge to the oil gallery near the oil filter. 2. Start the engine to check the relief valve opening pressure. Relief Valve Opening Pressure kPa (kg/cm /psi) Type1 559-618 (5.7-6.3/81.0-89.6)

  • Page 149: Oil Filter Cartridge

    6A1 – 14 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE OIL FILTER CARTRIDGE 6A1-14-1.tif REMOVAL • Place a receptacle beneath the oil filter to contain the drained oil. • Remove the oil filter cartridge using filter wrench. Filter wrench: 5-8840-0200-0 6A1-14-2.tif INSTALLATION • Lightly oil the O-ring of oil filter cartridge. •...
  • Page 150 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 15 CYLINDER HEAD COVER Removal steps 1. PCV hose 2. Cylinder head cover Installation steps To install, follow the removal steps in the reverse order. 6A1-15-1.tif REMOVAL Preparation: • Disconnect battery ground cable. 1. PCV Hose •...
  • Page 151 6A1 – 16 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 1. PCV Hose • Connect the PCV hose to the intake pipe. • Connect battery ground cable.
  • Page 152 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 17 ROCKER ARM SHAFT ASSEMBLY Removal steps 1. PCV hose 2. Cylinder head cover 3. Rocker arm shaft Assembly Installation steps To install, follow the removal steps in the reverse order. 6A1-17-1.tif REMOVAL Preparation: • Disconnect battery ground cable.
  • Page 153 6A1 – 18 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE Valve Clearance Adjustment Bring the piston in either the No.1 cylinder or the No.4 cylinder to TDC on the compression stroke by turning the crankshaft until the crankshaft damper pulley TDC line is aligned with the timing pointer. 6A1-18-1.tif "...
  • Page 154 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 19 2. Cylinder Head Cover • Install cylinder head cover and tighten bolts to the specified torque. N∙m (kg∙m/lb∙in) 13 (1.3/113) 1. PCV Hose • Connect battery ground cable.
  • Page 155 6A1 – 20 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE VALVESTEM OIL CONTROLLER & VALVE SPRING Removal steps 1. Cylinder head cover 2. Rocker arm shaft Assembly 3. Valve spring 4. Valve guide oil seal Installation steps To install, follow the removal steps in the reverse order. 6A1-20-1.tif REMOVAL Preparation:...
  • Page 156 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 21 4. Valve Guide Oil Seal • Removal valve guide oil seal by pliers. CAUTION • Removed oil controller should not be reused. 6A1-21-1.tif INSTALLATION 4. Valve Guide Oil Seal • Install new valve guide oil seal in valve. •...
  • Page 157 6A1 – 22 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE Valve Clearance Adjustment Above works refer to “ROCKER ARM SHAFT ASSEMBLY” Section in this manual. 1. Cylinder Head Cover • Apply engine oil to the rocker arms and the valve spring. • Install the cylinder head cover gasket to the cylinder head cover.
  • Page 158 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 23 TIMING GEAR (4JB1, 4JB1TC, 4JG2 Gear Type) 6A1-23-1.tif REMOVAL Preparation: • Disconnect battery ground cable. • Drain coolant. 1. Fan Shroud 2. Power Steering Pump Drive Belt (P/S Model) • Loosen power steering pump mounting bolt and adjust bolt, and remove the drive belt.
  • Page 159 6A1 – 24 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 7. Noise Cover Spacer 8. Timing Gear Case Cover 9. Oil Pipe 10. Idler Gear 1) Measure the camshaft timing gear backlash and the crankshaft timing gear backlash before removing the idler gear. 2) Measure the idler gear end play before removing the idler gear.
  • Page 160 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 25 11. Idle Gear 12. Injection Pump 1) Remove the six injection pump bracket bolts from the timing gear case. 6A1-25-1.tif " 2) Remove the injection pump rear bracket bolts from the injection pump bracket 3) Remove the injection pump rear bracket bolts the bracket from the cylinder body.
  • Page 161 6A1 – 26 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE INSTALLATION 14 Crankshaft Gear 1) Install the crankshaft gear. 2) Use the crankshaft gear installer to install the " crankshaft gear The crankshaft gear timing mark ("X-X") must be facing outward. Crankshaft Gear Installer: 9-8522-0020-0 6A1-26-1.tif 13.
  • Page 162 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 27 & 4) Install the injection pump rear bracket and the rear bracket bolts to the cylinder body. 5) Install the rear bracket bolts to the injection pump bracket Do not tighten the bolts. The rear bracket bolts will be finally tightened to the specified torque after tighten the injection pump nuts.
  • Page 163 6A1 – 28 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 10. Idler Gear 1) Apply engine oil to the idler gear and the idler gear shaft. 2) Align the idler gear "B" "Z" setting mark with the idler gear "A" "Z-Z" setting mark. 3) Tighten the idler gear bolt to the specified torque. N∙m (kg∙m/lb∙ft) 76 (7.7/56) 6A1-27-1.tif...
  • Page 164 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 29 3. AC Generator Drive Belt • Install AC Generator drive belt and adjust belt tension. • Depress the drive belt mid-portion with a 98N (10kg/22lb) force. Drive Belt Deflection mm (in) 8 (0.31) - 12 (0.47) •...
  • Page 165 6A1 – 30 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE TIMING BELT (4JG2 Belt Type) 6A1-30-1.tif REMOVAL Preparation: • Disconnect battery ground cable. • Drain coolant. 1. Cooling Fan Assembly • Remove clamp nut, and remove cooling fan asm, distant pipe, and fan pulley. 2.
  • Page 166 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 31 5. AC Generator Drive Belt • Loosen AC Generator mounting bolt (under side) and adjust plate lock bolt, and remove the drive belt. 6A1-31-1.tif 6. Power Steering Pump Bracket Assembly (P/S Model) • Loosen power steering oil pipe bracket and clip. •...
  • Page 167 6A1 – 32 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 11. Timing Belt • Prepare a fixing bolt (M8x40, P=1.25) • Turn crankshaft timing pulley in the normal direction pulley side mark to timing pulley housing side mark. • Make sure that the camshaft pulley and injection timing pulley fixing bolt holes are set to each other.
  • Page 168 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 33 • Mount new timing belt on pulleys in the following steps. → camshaft Crankshaft timing pulley " → Idle pulley → Injection Timing pulley → tensioner Pump pulley • Set the belt on crankshaft timing pulley and hold with one hand.
  • Page 169 6A1 – 34 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE CAUTION • In case where the timing belt has been replaced with the actuation of warning light, put off the light with change over switch on the reverse side of meter. • Refer to Chassis Electrical in Section 8. •...
  • Page 170 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 35 6. Power Steering Pump Bracket Assembly (P/S Model) • Install the pipe bracket & clip and tighten bolts to the specified torque. Pipe Bracket Bolts Torque N∙m (kg∙m/lb∙ft) 19 (1.9/14) Pipe Clip Bolts Torque N∙m (kg∙m/lb∙in) 10 (1.0/87) 6A1-35-1.tif...
  • Page 171 6A1 – 36 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 3. Power Steering Pump Drive Belt (P/S pump model) • Install PS pump drive belt and adjust belt tension. • Depress the drive belt mid-portion with a 98N (10kg/22lb) force. Drive Belt Deflection mm (in) 8 (0.31) - 12 (0.47) •...
  • Page 172 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 37 CYLINDER HEAD ASSEMBLY AND GASKET Removal steps 1. Radiator hose upper 2. Heater hose 3. A/C Compressor drive belt 4. Engine harness 5. Air intake duct 6. Injection pipe 7. Leak off pipe 8. PCV hose 9.
  • Page 173 6A1 – 38 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 2. Heater Hose • Disconnect heater hose from heater pipe. 3. A/C Compressor Drive Belt • Loosen idler lock nut. • Loosen adjust bolt and remove drive belt. 4. Engine Harness • Disconnect harness connectors from units on thermostat housing.
  • Page 174 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 39 9. Glow Plug Harness 10. Oil Level Gauge Guide Tube • Remove the guide tube from cylinder head. 6A1-39-1.tif 11. Oil Cooler Water Pipe (Oil Cooler Model) • Remove the pipe fixing bolt of cylinder head rear side. •...
  • Page 175 6A1 – 40 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 15. By-pass Hose 16. Cylinder Head Cover 6A1-40-1.tif 17. Rocker Arm Shaft • Loosen the rocker arm shaft bracket bolts a little at a time in the numerical order shown in the illustration. NOTE: Failure to loosen the rocker arm shaft bracket bolts a little at a time in numerical order will adversely effect the rocker arm shaft.
  • Page 176 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 41 INSTALLATION 20. Cylinder Head Gasket Cylinder head gasket is determined by the piston head projection from the cylinder body upper surface, in order to improve engine performance. Three types of gasket are provided by the difference of thickness.
  • Page 177 6A1 – 42 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 4JG2 Cylinder Head Gasket Thickness mm (in) Piston Gasket Thickness Gasket Grade Mark Projection (Reference) 0.658 - 0.713 1.60 (0.026 - 0.028) (0.0630) 0.713 - 0.759 1.65 (0.028 - 0.030) (0.0650) 0.759 - 0.814 1.70 (0.030 - 0.032) (0.0670)
  • Page 178 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 43 3) Tighten the rocker arm shaft bracket bolts to the specified torque in the numerical order shown in the illustration. Rocker Arm Shaft Bracket Bolt Torque N∙m (kg∙m/lb∙ft) 54 (5.5/40) • Valve clearance adjustment. 6A1-43-1.tif...
  • Page 179 6A1 – 44 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE Valve Clearance Adjustment Above works refer to “ROCKER ARM SHAFT ASSEMBLY” Section in this manual. 16. Cylinder Head Cover • Apply engine oil to the rocker arms and the valve spring. • Install the cylinder head cover gasket to the cylinder head cover.
  • Page 180 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 45 11. Oil Cooler Water Pipe (Oil Cooler Model) • Install the water pipe bolt and tighten bolt to the specified torque. Water Pipe Nut Torque N∙m (kg∙m/lb∙ft) 19 (1.9/14) Pipe Bracket Bolt Torque N∙m (kg∙m/lb∙ft) 40 (4.1/30) 6A1-45-1.tif 10.
  • Page 181 6A1 – 46 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 5. Air Intake Duct 4. Engine Harness • Connect the thermo-sensor harness and thermo-meter unit harness. 6A1-46-1.tif 3. A/C Compressor Drive Belt (A/C Model) Check drive belts for wear or damage, and replace with new ones as necessary.
  • Page 182 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 47 2. Heater Hose • Connect the heater hose them tighten clip securely. 1. Radiator Hose Upper • Connect the radiator hose them tighten clip securely. • Pour coolant • Connect battery ground cable. • Start the engine and check coolant leakage.

  • Page 183: Oil Pan

    6A1 – 48 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE OIL PAN Removal steps 1. Vacuum pump oil hose 2. Engine mount bolts 3. Stiffener and space rubber 4. Oil pan Assembly Installation steps To install, follow the removal steps in the reverse order 6A1-48-1.tif REMOVAL Preparation:...
  • Page 184 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 49 2. Engine Mount Bolts • Remove the engine mount bolts right & left side. 6A1-49-1.tif 3. Stiffener & Space Rubber • Remove the exhaust pipe bracket. • Remove the stiffener from of the oil pan left & right side.
  • Page 185 6A1 – 50 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE INSTALLATION 4. Oil Pan Assembly • Apply the recommended liquid gasket or its equivalent to the No.5 bearing cap arches, the grooves, and the timing gear case arches at the positions shown in the illustration.

  • Page 186: Oil Pump Assembly

    4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 51 OIL PUMP ASSEMBLY Removal steps 1. Vacuum pump oil hose 2. Engine mount bolts 3. Stiffener and space rubber 4. Oil pan Assembly 5. Oil pump Assembly Installation steps To install, follow the removal steps in the reverse order.
  • Page 187 6A1 – 52 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 2. Engine Mount Bolts • Remove the engine mount bolts right & left side. 6A1-52-1.tif 3. Stiffener & Space Rubber • Remove the exhaust pipe bracket. • Remove the stiffener from of the oil pan left & right side.
  • Page 188 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 53 INSTALLATION • Prepare a solution of 80% engine oil and 20% molybdenum disulfide. • Apply and ample coat of the solution to the teeth of the oil pump pinion. 5. Oil Pump Assembly • Apply engine oil to oil pipe O-ring and insert the O-ring in O-ring hold on cylinder block.
  • Page 189 6A1 – 54 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE PISTON, PISTON RING AND CONNECTING ROD 6A1-45-1.tif REMOVAL Preparation: • Disconnect battery ground cable • Drain coolant • Drain engine oil NOTE • Install drain plug with new washer. N∙m (kg∙m/lb∙ft) 44 (4.5/33) 1. Cylinder Head Assembly 1) Radiator hose upper 2) Heater hose 3) A/C compressor drive belt...
  • Page 190 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 55 6) Injection pipe 7) Leak off pipe 8) PCV hose 9) Glow plug harness 10) Oil level gauge guide tube 11) Oil cooler water pipe (Oil Cooler Model) 12) A/C compressor assembly (A/C Model) 13) Vacuum actuator hose (Exhaust Brake Model) 14) Front exhaust pipe 15) By-pass hose...
  • Page 191 6A1 – 56 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 6. Piston and Connecting Rod Assembly 1) Remove carbon deposits from the upper portion of the cylinder wall with a scraper before removing the piston and connecting rod. 6A1-56-1.tif 2) Move the piston to the top of the cylinder and tap it with a hammer grip or similar object from the connecting rod lower side to drive it out.
  • Page 192 When changing piston/connecting rod combinations, do not change the piston/piston pin combination. 4) Install the piston to the connecting rod. The piston head front mark and the connecting rod " "ISUZU" casting mark must be facing the same direction. 6A1-57-3.tif...
  • Page 193 6A1 – 58 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 5) Apply a coat of engine oil to the piston pin and the piston pin hole. Use your fingers to force the piston pin into the piston until it makes contact with the snap ring. 6A1-58-1.tif 6) Use your fingers to force the piston pin snap ring into the piston snap ring groove.
  • Page 194 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 59 9) Apply engine oil to the piston ring surfaces. 10) Check that the piston rings rotate smoothly in the piston ring grooves. 11) Position the piston ring gaps as shown in the illustration. 6A1-59-1.tif 12) Carefully wipe any oil or other foreign material from the connecting rod bearing back face and the connecting rod bearing fitting surface.
  • Page 195 6A1 – 60 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 3) Apply a coat of engine oil to the threads and setting faces of each connecting rod cap bolt. 4) Tighten the connecting rod bearing cap bolts to the specified torque in two steps using the Angular Tightening Method.
  • Page 196 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 61 2) Fit the gasket rear lipped portion into the No.5 groove. Be absolutely sure that the lipped portion is fitted snugly into the groove. 3) Install the oil pan to the cylinder body. • Tighten the oil pan bolts to the specified torque.
  • Page 197 6A1 – 62 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 1. Cylinder Head ASM 1) Cylinder head gasket 2) Cylinder head assembly 3) Push rod 4) Rocker arm shaft 5) Valve clearance adjustment 6) Cylinder head cover 7) By-pass hoses 8) Front exhaust pipe 9) Vacuum actuator hose (Exhaust Brake Model) 10) A/C compressor assembly (A/C Model) 11) Oil cooler water pipe (Oil Cooler Model)
  • Page 198 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 63 CAMSHAFT AND TAPPET Removal steps 1. Transmission and clutch Assembly 2. Engine Assembly 3. Cylinder head Assembly and gasket 4. Timing gear (Gear drive model) 4a. Timing belt (Belt drive model) 5. Oil pan 6.
  • Page 199 6A1 – 64 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 1. Transmission and Clutch Assembly 1) Transmission 2) Clutch 2. Engine Assembly 1) Radiator assembly 2) Intake air duct 3) Heater hose 4) Engine control cable 5) Glow plug harness 6) Fuel hose 7) Oil pressure switch harness 8) A/C compressor assembly (A/C Model) 9) Power steering pump &...
  • Page 200 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 65 4a. Timing Belt (Belt Drive Model) 1) Cooling fan assembly 2) Crankshaft damper pulley 3) Timing pulley upper cover 4) Timing pulley lower cover 5) Flange: camshaft pulley 6) Flange: injection pump pulley 7) Timing belt Above works refer to “TIMING BELT (Belt Type)”...
  • Page 201 6A1 – 66 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE • Remove the center bolt and remove the timing pulley with pulley center. 6A1-66-1.tif • Remove the oil seal retainer. 6A1-66-2.tif 5. Oil Pan Assembly • Disconnect vacuum pump oil hose from oil pan. 6A1-66-3.tif •...
  • Page 202 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 67 7. Camshaft and Tappets • Remove the camshaft from cylinder body. • Take care not to damage the camshaft bearings. 6A1-67-1.tif • Take out the tappets from cylinder body. 6A1-67-2.tif...
  • Page 203 6A1 – 68 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE INSTALLATION 7. Camshaft and Tappets • Apply a coat of engine oil to the tappet and the cylinder body tappet insert holes. • Locate the position mark applied at disassembly (if the tappet is to be reused). NOTE: The tappet must be installed before the camshaft.
  • Page 204 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 69 4. Timing Gear (Gear Type) 6) Camshaft timing gear 5) Timing gear case cover 4) Noise cover spacer 3) Noise shield cover 2) Crankshaft damper pulley 1) Cooling fan assembly Above works refer to “TIMING GEAR (Gear Type)” Section in this manual.
  • Page 205 6A1 – 70 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 1. Transmission and Clutch Assembly 2) Clutch 1) Transmission Above works refer to “ENGINE ASSEMBLY” Section in this manual. • Connect the battery ground cable. • Pour coolant • Pour engine oil • Start the engine and check coolant leakage.
  • Page 206 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 71 CRANKSHAFT FRONT OIL SEAL (Gear Drive Type) Removal steps 1. Fan shroud 2. Power steering pump drive belt 3. AC generator drive belt 4. Cooling fan Assembly 5. Crankshaft damper pulley 6. Front oil seal Installation steps To install, follow the removal steps in the reverse order.
  • Page 207 6A1 – 72 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 6. Front Oil Seal • Use a plastic hammer and a screwdriver to top around the oil seal to free it from the gear case cover. Take care not to damage the oil seal fitting surfaces. 6A1-72-1.tif INSTALLATION 6.
  • Page 208 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 73 CRANKSHAFT FRONT OIL SEAL (Belt Drive Type) 6A1-73-1.tif REMOVAL Preparation: • Disconnect battery ground cable. • Drain coolant. 1. Cooling Fan Assembly 2. Fan Shroud 3. Power Steering Pump Drive Belt (P/S Model) 4. A/C Compressor Drive Belt (A/C Model) 5.
  • Page 209 6A1 – 74 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 12. Crankshaft Pulley Center • Remove the pulley center by using special tool. Remover: 5-8840-0161-0 13. Crankshaft Timing Pulley 14. Front Oil Seal • Remove the oil seal by using special tool. • With the oil seal pushed in deep, install the special tool as shown in the illustration to remove the oil seal.
  • Page 210 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 75 11. Timing Belt 10. Flange; Camshaft Pulley 9. Timing Pulley Lower Cover 8. Timing Pulley Upper Cover 7. Crankshaft Damper Pulley 6. Power Steering Pump Bracket Assembly (P/S Model) 5. AC Generator Drive Belt 4.
  • Page 211 6A1 – 76 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE CRANKSHAFT REAR OIL SEAL (Gear & Belt Drive Type) Removal steps 1. Transmission and clutch Assembly 2. Flywheel 3. Rear oil seal Installation steps To install, follow the removal steps in the reverse order. 6A1-76-1.tif REMOVAL Preparation:...
  • Page 212 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 77 Wiring Connector • Disconnect the wiring connectors from the car speed sensor, the neutral switch and the back-up light switch. Shift Cable and Select Cable • Disconnect the shift cable and select cable on the transmission side.
  • Page 213 6A1 – 78 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE Transmission Assembly NOTE: The exhaust pipe bracket, the gear control bracket and the clips are sometimes installed in the wrong position or direction confusedly. To prevent incorrect installation of these parts, put a correct installation mark on them.
  • Page 214 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 79 2) Clutch • Raise vehicle and support with suitable safety stands. CAUTION: Do not let clutch fluid remain on a painted surface, Wash it off immediately. Pressure Plate Assembly " Driven Plate Assembly • Use the pilot aligner to prevent the driven plate assembly from falling free.
  • Page 215 6A1 – 80 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE INSTALLATION 3. Rear Oil Seal • Use the oil seal installer the oil seal to the cylinder body. Rear oil seal Install: 5-8840-2359-0 NOTE: Wipe off rust and scraps clean from the press-in portion of the oil seal. 6A1-80-1.tif Take note of the press-in direction of the oil seal.
  • Page 216 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 81 Pressure Plate Assembly • Tighten pressure plate assembly fixing bolts in numerical order. Pressure Plate Fixing Bolt Torque N∙m (kg∙m/lb∙ft) 18 (1.8/13) • Remove the pilot aligner. NOTE: In case a new pressure plate assembly is mounted, 6A1-81-1.tif after tightening a pressure plate at the specified torque, be sure to remove the wiring for protection of...
  • Page 217 6A1 – 82 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE Front Exhaust Pipe Front Exhaust Pipe Bolts Torque N∙m (kg∙m/lb∙ft) 37 (3.8/27) & Exhaust Brake Assembly Exhaust Brake Bolts Torque N∙m (kg∙m/lb∙ft) 17 (1.8/12) Clutch Slave Cylinder Slave Cylinder Bolts Torque N∙m (kg∙m/lb∙ft) 19 (1.9/14) •...
  • Page 218 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 83 FLYWHEEL AND PILOT BEARING Removal steps 1. Transmission and clutch Assembly 2. Pilot bearing 3. Flywheel Installation steps To install, follow the removal steps in the reverse order. 6A1-83-1.tif REMOVAL Preparation: • Disconnect battery ground cable. 1.
  • Page 219 6A1 – 84 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE INSTALLATION 3. Flywheel • Apply engine oil to fixing bolts. • Tighten the flywheel bolts to the specified torque in two steps using the Angular Tightening Method. Follow the numerical order shown in the illustration. Flywheel Bolt Torque N∙m (kg∙m/lb∙ft) 1st Step...
  • Page 220 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 85 CRANKSHAFT AND MAIN BEARINGS Removal steps 1. Transmission and clutch Assembly 2. Engine Assembly 3. Cylinder head Assembly and gasket 4. Timing gear (Gear drive model) 4a. Timing belt (Belt drive model) 5. Oil pan Assembly 6.
  • Page 221 6A1 – 86 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE REMOVAL Preparation: • Disconnect battery ground cable. • Drain coolant from the radiator and engine. 1. Transmission and Clutch Assembly 1) Transmission 2) Clutch Above works refer to “ENGINE ASSEMBLY” Section in this manual. 2.
  • Page 222 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 87 4. Timing Gear (Gear Drive Model) 1) Cooling fan assembly 2) Crankshaft damper pulley 3) Noise shield cover 4) Noise cover spacer 5) Timing gear case cover 6) Oil pipe 7) Idle gear 8) Idle gear “B" and shaft 9) Injection pump 10) Camshaft timing gear Above works refer to “TIMING GEAR (Gear Type)”...
  • Page 223 6A1 – 88 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 9) Crankshaft timing pulley • Block the crankshaft with a piece of hard wood. • Use the crankshaft timing pulley puller to remove the timing pulley. Crankshaft Timing Pulley Puller: 5-8840-2035-0 6A1-88-1.tif 10) Injection pump timing pulley 11) Injection pump Above works refer to “CYLINDER BLOCK ASSEMBLY”...
  • Page 224 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 89 • If the connecting rod upper bearings are to be reinstalled, mark their fitting positions by tagging each bearing with the cylinder number from which it was removed. 6A1-89-1.tif 9. Front Oil Seal (Belt Drive Model) •...
  • Page 225 6A1 – 90 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE INSTALLATION 14. Crankshaft and Main Bearings • The crankshaft upper bearings have an oil hole and an oil groove. The lower bearings do not… • Install main bearings in the cylinder body and main bearing cap respectively.
  • Page 226 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 91 • Install the bearing caps with the bearing cap head arrow mark facing the front of the engine. • Apply engine oil to the front of the engine. • Tighten the crankshaft bearing cap bolts to the specified torque a little at a time in the sequence shown in the illustration.
  • Page 227 6A1 – 92 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE • Block the crankshaft with a piece of hard wood to prevent the flywheel form turning. • Apply a coat of engine oil to the threads of the flywheel bolts. • Align the flywheel with the crankshaft dowel pin. •...
  • Page 228 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 93 2) With the edge of the oil seal attached securely to the crankshaft, tighten it with the center bolt until the sleeve hits securely against the reference plane at the front end of the crankshaft. 3) Remove the sleeve.
  • Page 229 6A1 – 94 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 2) Crankshaft damper pulley 1) Cooling fan assembly Above works refer to “TIMING GEAR (Belt Type)” Section in this manual. 4. Timing Gear (Gear Drive Model) 11) Crankshaft gear • Install the crankshaft gear. •...
  • Page 230 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 95 2. Engine Assembly 13) Support rubber 12) Front exhaust pipe 11) Vacuum pump hose 10) Actuator vacuum hose (Exhaust Brake Model) 9) Power steering pump & bracket assembly (Power Steering Model) 8) A/C compressor assembly (A/C Model) 7) Oil pressure switch harness 6) Fuel hose 5) Glow plug harness...

  • Page 231: Engine Assembly

    6A1 – 96 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE ENGINE ASSEMBLY Removal steps 1. Transmission and clutch Assembly 2. Radiator Assembly 3. Intake air duct 4. Heater hose 5. Engine control cable 6. Glow plug harness 7. Fuel hose 8. Oil pressure switch harness 9.
  • Page 232 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 97 1. Transmission and Clutch Assembly • Raise vehicle and support with suitable safely. 1) Transmission Propeller Shaft • Reference mark the flange yoke to the parking brake drum. • Disconnect the propeller shaft at flange yoke. •...
  • Page 233 6A1 – 98 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE Clutch Slave Cylinder • Remove the clutch pipe fixing clips and the clip bracket (Right hand drive models only). 6A1-98-1.tif • Remove the slave cylinder assembly with the flexible hose attached, and then tie it to the frame so that it does not interface with servicing work.
  • Page 234 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 99 • Remove the nuts of the transmission mounting bracket on the crossmember side. • Engine and transmission angles may need to be adjusted for removal. • Hold the rear section of the engine by the jack or hoist. CAUTION: When lifting the engine by the jack, use wood blocks to prevent any possible damage to the oil pan.
  • Page 235 6A1 – 100 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 2. Radiator Assembly 1) Remove the radiator hose upper and lower. 2) Remove the reservoir tank hose 3) Remove the cushion rubbers on both sides. 4) Remove the radiator stay. 6A1-100-1.tif 3. Intake Air Duct 4.
  • Page 236 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 101 10. Power Steering Pump & Bracket Assembly (Power Steering Model) 1) Loosen the idler pulley lock nut. 2) Loosen the adjust bolt then remove the drive belt. 3) Remove the pipe bracket fixing bolt and clip. 4) Remove the power steering pump fixing bolts pump to chassis frame side use the wire.
  • Page 237 6A1 – 102 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 2) Left Hand • Remove two fixing nuts at the crossmember side. 15. Engine Assembly 1) Lift engine carefully by using hoist. 2) Lift front part of engine higher than rear part of it. 3) Take out engine assembly taking care not to damage full pipes, brake pipes and etc.
  • Page 238 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 103 INSTALLATION 15. Engine Assembly • Position engine mountings by using hoist. 14. Support Rubber • After all fixing bolts (left:two bolts, right:two bolts) were inserted to every holes, and engine asm and tighten fixing bolts to the specified torque. N∙m (kg∙m/lb∙ft) 40 (4.1/30) 6A1-103-1.tif...
  • Page 239 6A1 – 104 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 10. Power Steering Pump & Bracket Assembly (Power Steering Model) • Install the power steering pump and pipe bracket then tighten bolts to the specified torque. Pump Bolts Torque N∙m (kg∙m/lb∙ft) 19 (1.9/14) Pipe Bracket Bolts Torque N∙m (kg∙m/lb∙ft) 19 (1.9/14) 6A1-104-1.tif...
  • Page 240 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 105 • Install A/C compressor drive belt and adjust belt tension. Check drive belts for wear or damage, and replace with new ones as necessary. Check belts for tension, and adjust as necessary. • Push the middle of belts with a force of 10kg and check each bolt for deflection.
  • Page 241 6A1 – 106 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE 4. Heater Hose • Connect the heater hose then tighten clip securely. 3. Intake Air Duct • Connect the air duct then tighten clip securely. 6A1-106-1.tif 2. Radiator Assembly 1) Install the cushion rubber on both sides. 2) Install the radiator stay 3) Connect the radiator hose upper and lower.
  • Page 242 4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 107 1) Transmission Mounting Bracket Mounting Bracket Nuts Torque N∙m (kg∙m/lb∙ft) 69 (7.0/51) Transmission Assembly • Support the transmission with mission jack. CAUTION: To prevent the falling of the transmission, tie it securely to the jack with a chain or belt. •...
  • Page 243 6A1 – 108 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE Front Exhaust Pipe Front Exhaust Pipe Bolts Torque N∙m (kg∙m/lb∙ft) 37 (3.8/27) & Exhaust Brake Assembly Exhaust Brake Bolts Torque N∙m (kg∙m/lb∙ft) 1 7(1.8/12) Clutch Slave Cylinder Slave Cylinder Bolts Torque N∙m (kg∙m/lb∙ft) 19 (1.9/14) •...
  • Page 244 HOME ENGINE COOLING 6B - 1 SECTION 6B ENGINE COOLING CONTENTS PAGE General Description......................6B - 1 On-Vehicle Service ......................6B - 6 Water Pump........................6B - 6 Thermostat ........................6B -10 Radiator ........................6B -12 Drive Belt Adjustment ....................6B -15 GENERAL DESCRIPTION 6B-1-1.tif...

  • Page 245: Water Pump

    6B - 2 ENGINE COOLING The cooling system is a pressurized coolant forced circulation type which consists of water pump, thermostat cooling fan, radiator and other components. The circulating coolant cools the lubricating oil in the oil filter and turbocharger. WATER PUMP The coolant pump is a centrifugal impeller type and is driven by V type drive belt.
  • Page 246 Replace damaged rubber hoses as the engine anti- freeze coolant is liable to leak out even minor cracks. Isuzu recommends to use Isuzu genuine anti-freeze (ethylene-glycol based) or equivalent, for the cooling system and not add any inhibitors or additives.
  • Page 247 6B - 4 ENGINE COOLING 7. Install and tighten radiator cap and start the engine. After idling for 2 to 3 minutes, stop the engine and reopen radiator cap. If the water level is lower, replenish. WARNING: When the coolant is heated to a high temperature, be sure not to loosen or remove the radiator cap.
  • Page 248 Proper mixing ratio can be determined by referring to the chart. Supplemental inhibitors or additives claiming to increase cooling capability that have not been specifically approved by Isuzu are not recommended for addition to the cooling system. 6B-4-1.tif •...
  • Page 249 6B - 6 ENGINE COOLING ON-VEHICLE SERVICE WATER PUMP Removal steps 1. Fan shoroud 2. Cooling fan Assembly 3. Power steering pump drive belt 4. A/C compressor drive belt 5. AC generator drive belt 6. Crankshaft damper pulley 7. Timing pulley upper cover 8.
  • Page 250 ENGINE COOLING 6B - 7 5. AC Generator Drive Belt • Loosen AC Generator mounting bolt (under side) and adjust plate lock bolt, and remove the drive belt. 6B-6-1.tif 6. Crankshaft Damper Pulley 6B-6-2.tif 7. Timing Pulley Upper Cover 8. Timing Pulley Lower Cover 9.
  • Page 251 6B - 8 ENGINE COOLING INSTALLATION 9. Water Pump Assembly • Set O-ring in water pump body groove. • Install water pump assembly, and tighten to specified torque. Pump Fixing Bolt Torque N∙m (Kg∙m/lb∙ft) 20 (2.0/14) 8. Timing Pulley Lower Cover 6B-7-1.tif •...
  • Page 252 ENGINE COOLING 6B - 9 Generator Fixing Belt Torque N∙m (Kg∙m/lb∙ft) 40 (4.1/30) Adjust Plate Fixing Belt Torque N∙m (Kg∙m/lb∙ft) 19 (1.9/14) A/C Idler Pulley Lock Nut Torque N∙m (Kg∙m/lb∙ft) 27 (2.8/20) 6B-8-1.tif P/S Idler Pulley Lock Nut Torque N∙m (Kg∙m/lb∙ft) 27 (2.8/20) 2.
  • Page 253 6B - 10 ENGINE COOLING THERMOSTAT 6B-9-1.tif REMOVAL Preparation: • Disconnect battery ground cable. • Drain coolant from the radiator and engine. 1. Switch Harness 2. Outlet Pipe • Remove mounting bolt and remove outlet pipe together with radiator hose. 3.
  • Page 254 ENGINE COOLING 6B - 11 INSTALLATION 4. Thermostat 3. Gasket 2. Outlet Pipe • Connect outlet pipe and tighten bolts to the specified torque. N∙m (Kg∙m/lb∙ft) 19 (1.9/14) 6B-10-1.tif 1. Switch Harness • Install switch harness. • Install battery ground cable. •...
  • Page 255 6B - 12 ENGINE COOLING RADIATOR 6B-11-1.tif REMOVAL Preparation: • Disconnect battery ground cable. • Loosen drain plug to drain coolant. 1. Reservoir Tank Hose & Bypass Hose • Disconnect the hose from radiator. 2. Radiator Hose • Disconnect lower hose and upper hose from the engine.
  • Page 256 ENGINE COOLING 6B - 13 7. Radiator Assembly • Remove upward the radiator assembly with hose, taking care not to damage the radiator core by fan blade. INSPECTION Radiator Valve • Apply air pressure from filler neck using radiator cap tester and check the opening pressure of radiator valve.
  • Page 257 6B - 14 ENGINE COOLING INSTALLATION 7. Radiator Assembly • Install the radiator 6. Cushion Rubber • Install cushion rubbers on both sides of radiator bottom. • Install radiator assembly with hose, taking care not to damage the radiator core by a fan blade. 5.

  • Page 258: Drive Belt Adjustment

    ENGINE COOLING 6B - 15 DRIVE BELT ADJUSTMENT 6B-14-1.tif INSPECTION Check drive belts for wear or damage, and replace with new ones as necessary. Check belts for tension, and adjust as necessary. • Check drive belts tension. • Push the middle of belts with a force of 98 N (10 kg/22 lb) and check each bolt for deflection.
  • Page 259 6B - 16 ENGINE COOLING TENSION ADJUSTMENT 1. Cooling Fan Pulley Belt • With AC Generator mounting and lock bolts loose, adjust belt tension with adjuster's adjust bolt. Tighten bolt to the specified torque Generator Fixing Bolt Torque N∙m (Kg∙m/lb∙ft) 40 (4.1/30) Adjust Plate Fixing Bolt Torque N∙m (Kg∙m/lb∙ft)

  • Page 260: Engine Fuel

    HOME ENGINE FUEL 6C - 1 SECTION 6C ENGINE FUEL CONTENTS PAGE General Description....................... 6C - On-Vehicle Service ......................6C - Fuel Filter Assembly....................6C - Fuel Filter Cartrige..................... 6C - Injection nozzle......................6C - Injection Pump Assembly (Gear Drive Type) ............6C - 26 Injection Pump Assembly (Belt Drive Type)............
  • Page 261 6C - 2 ENGINE FUEL GENERAL DESCRIPTION When working on the fuel system, there are Clean and inspect "O" rings. Replace where several things to keep in mind: required. • Any time the fuel system is being worked on, • Always relieve the line pressure before disconnect the negative battery cable except servicing any fuel system components.
  • Page 262 ENGINE FUEL 6C - 3 FUEL FLOW 6C-2-1.tif The fuel system consists of the fuel tank, the water Fuel, fed by the injection pump plunger, is delivered to separator, the fuel filter, the injection pump, and the the injection nozzle in the measured volume at the injection nozzle.

  • Page 263: Injection Pump

    6C - 4 ENGINE FUEL INJECTION PUMP 6C-3-1.tif 6C-3-2.tif A Bosch Distributor Type Injection Pump is used. A The injection pump is compact, light weight, and single reciprocating/revolving plunger delivers the fuel provides reliable high-speed operation. uniformly to the injection nozzles, regardless of the An aneroid compensator is available as an option for number of cylinders.
  • Page 264 ENGINE FUEL 6C - 5 FUEL FILTER AND WATER SEPARATOR 6C-4-1.tif 6C-4-2.tif A cartridge type fuel filter and a water separator are The water separator has an internal float. When the used along with the VE type injection pump. float reaches the specified level, a warning light comes on to remind you to drain the water from the As the inside of the injection pump is lubricated by the water separator.

  • Page 265: Injection Nozzle

    6C - 6 ENGINE FUEL INJECTION NOZZLE 6C-5-1.tif For 4J Series diesel engines, there are two types 4JB1-TC Engine available: Direct injection engine (4JB1/4JB1T) and The two-spring nozzle holder has been developed to Indirect injection engine (4JG2). Accordingly, the reduce NOx (Nitrogen Oxides) and particulates from injection nozzles to be used are different depending on direct injection diesel engine exhaust.

  • Page 266: Fuel Filter Assembly

    ENGINE FUEL 6C - 7 ON-VEHICLE SERVICE FUEL FILTER ASSEMBLY 6C-6-1.tif REMOVAL Preparation • Disconnect battery ground cable. 1. Fuel Filler Cap 2. Fuel Hose • Disconnect fuel hose from filter body. Plug the hose ends to prevent fuel spillage. 3.
  • Page 267 6C - 8 ENGINE FUEL FUEL FILTER CARTRIDGE REMOVAL • Remove the cartridge using a filter wrench. Filter wrench: 5-8840-0253-0 (J-22700) INSTALLATION • Clean the cartridge mounting surface of filter body so that the cartridge can be securely. Apply engine oil thinly to new cartridge O-ring. •...
  • Page 268 ENGINE FUEL 6C - 9 INJECTION NOZZLE Removal steps 1. Injection pipe 2. Leak off pipe or hose 3. Injection nozzle Installation steps To install, follow the removal steps in the reverse order. 6C-8-1.tif REMOVAL Preparation: • Disconnect battery ground cable. 1.
  • Page 269 6C - 10 ENGINE FUEL DISASSEMBLY (4JG2 Engine) • Grip nozzle holder with a vise, loosen retaining nut and disassemble. • Loosen holder nut and remove the nozzle. 6C-9-1.tif CAUTION • Be careful not to damage the needle valve. • Remove spacer, positioning pin, and push rod.
  • Page 270 ENGINE FUEL 6C - 11 CAUTION • If the needle valve does not slide smoothly repair or replace with a new nozzle assembly. Nozzle lapping procedure • Apply thinly a compound (Chrome oxide kneaded with an animal oil) to the seat of needle valve and lap. 6C-10-1.tif CAUTION •...
  • Page 271 6C - 12 ENGINE FUEL • Install retaining nut and tighten nut to the specified torque. N∙m (Kg∙m/lb∙ft) 39 (4.0/32) 6C-11-1.tif ADJUSTMENT OF INJECTION OPENING PRESSURE (4JG2 Engine) • Set nozzle holder assembly on a nozzle tester. • Apply hydraulic pressure by operating tester handle, and make sure fuel cam be injected under the following pressure.
  • Page 272 ENGINE FUEL 6C - 13 INSTALLATION (4JG2 Engine) CAUTION • Nozzle and assembling should be as illustrated. • Use new heat shield and new corrugated washer. 6C-12-1.tif 3. Injection Nozzle (4JG2 only) • Lightly tighten the holder nut to suck extent that the nozzle holder can turn one word and one word.
  • Page 273 6C - 14 ENGINE FUEL 4-1 Injection Nozzle (Two spring nozzle holder) (4JB1-TC only) The two-spring nozzle holder has been developed to reduce NOx (Nitrogen Oxides) and particulates from direct injection diesel engine exhaust. DISASSEMBLY 1. Retaining nut 2. Nozzle & pin 3.
  • Page 274 ENGINE FUEL 6C - 15 REASSEMBLY AND OPENING PRESSURE ADJUSTMENT (4JB1-TC only) 1. Nozzle holder body 2. Shim (First opening pressure adjustment) 3. First spring 4. Spring seat 5. Collar 6. Second spring 7. Push rod 8. Shim (Second opening pressure adjustment) 9.
  • Page 275 6C - 16 ENGINE FUEL First nozzle opening pressure adjustment 1. Claim the nozzle holder in a vise. 040MV015.tif 2. Install the shim, first spring and spring seat in the nozzle holder. 040MV016.tif 3. Install the collar, second spring, shim, spring seat and pushrod in the nozzle holder.
  • Page 276 ENGINE FUEL 6C - 17 7. Hand-tighten the adjustment retaining nut together with the gasket to the nozzle holder. Retaining nut: 5-8677-7140-0 Gasket: 5-8677-7139-0 040MV010.tif 8. Tighten the adjustment retaining nut to the specified torque. Torque: 29 - 39 N∙m (3.0 - 4.0 kg∙m) 040MV014-1.tif 9.
  • Page 277 6C - 18 ENGINE FUEL Full needle valve lift confirmation 1. Install the gasket and plug on the adjustment retaining nut. Gasket: 8-9722-7602-0 Plug: 5-8677-7141-0 040MV013.tif 2. Position the nozzle holder with the nozzle facing down and install the dial gauge holder on the nozzle holder. Dial gauge holder: 5-8677-7142-0 040MV012.tif 3.
  • Page 278 ENGINE FUEL 6C - 19 5. Secure the dial gauge to the nozzle holder using the nut so that the pin contacts the tip of the first spring seat. CAUTION: • Secure the dial gauge so that a stroke of 2 mm can be measured.
  • Page 279 6C - 20 ENGINE FUEL Pre-lift confirmation 1. With the needle valve at full lift, release the nozzle tester handle. Note: The in-line pressure will decrease and needle valve lift (as indicated on the dial gauge) will also decrease a little. 040MV007.tif 040MV006.tif 2.
  • Page 280 ENGINE FUEL 6C - 21 Second nozzle opening pressure confirmation 1. After pre-lift confirmation, operate the nozzle tester to increase in-line pressure to 34.3 - 44.1 MPa (350 - 450 kg/cm ) so that the nozzle’s needle valve moves through its full lift. 040MV030.tif 2.
  • Page 281 6C - 22 ENGINE FUEL Second nozzle opening pressure adjustment If the second nozzle opening pressure is not as specified, disassemble the nozzle from the nozzle holder and replace the shim until the pressure is as specified. CAUTION: • Because the second opening pressure changes when the first opening pressure changes, the second opening pressure must be adjusted when the first opening pressure changes.
  • Page 282 ENGINE FUEL 6C - 23 DISASSEMBLY (4JBI/4JB1T Engine) 1. Retaining Nut 2. Injection Nozzle 1) Remove the nozzle assemblies from the nozzle holders. Tag the nozzle assemblies and the nozzle holders to ensure that they are reinstalled in their original positions.
  • Page 283 6C - 24 ENGINE FUEL Nozzle Lapping Procedure " 1. Lap the nozzle needle and the nozzle body applying a compound of oxidized chrome and animal NOTE: Do not apply an excessive amount of the oxidized chrome and animal oil compound to the injection needle valve seat area.
  • Page 284 ENGINE FUEL 6C - 25 Injection Nozzle Adjustment 1) Attach the injection nozzle holder to the injection nozzle tester. 2) Apply pressure to the nozzle tester to check that the injection nozzle opens at the specified pressure. kPa (kg/cm /psi) 18,142 (185/2630) If the injection nozzle does not open at the specified pressure, install or remove the appropriate number of...
  • Page 285 6C - 26 ENGINE FUEL INJECTION PUMP ASM (4JB1/4JB1T, 4JG2 Gear Drive Type) 6C-25-1.tif REMOVAL Preparation: • Disconnect battery ground cable. • Drain coolant. 1. Cooling Fan Assembly • Remove clamp nut, and remove cooling fan assembly, distant pipe, and fan pulley. 2.
  • Page 286 ENGINE FUEL 6C - 27 5. AC Generator Drive Belt • Loosen AC generator mounting bolt (under side) and adjust plate lock bolt, and remove the drive belt. 6. Noise Shield Cover 7. Noise Cover Spacer 8. Air Intake Duct 6C-26-1.tif 9.
  • Page 287 6C - 28 ENGINE FUEL INSTALLATION 14. Injection Pump Assembly 1. Timing gear case a camshaft timing gear side c injection pump timing gear side check holde cover. 2. Turn the crankshaft clockwise to see the TDC mark of the crank pulley to the pointer, and then bring the No. 1 cylinder to the TDC on the compression stroke.
  • Page 288 ENGINE FUEL 6C - 29 10. Fuel Hose • Connect the fuel feed hose and fuel return hose. • Connect the leak off hose. 9. Injection Pump Control Cable 1) Install the control wire to the engine control lever. 2) Hold the accelerator lever in the fully closed position and stretch the control cable in the direction indicated by the arrow to remove any slack.
  • Page 289 6C - 30 ENGINE FUEL 4. A/C Compressor Drive Belt (A/C Model) • Install A/C compressor drive belt and adjust belt tension. • Depress the drive belt mid-portion with a 98N (10 kg/22 lb) force. Drive Belt Deflection mm (in) 8 (0.31) - 10 (0.39) •...
  • Page 290 ENGINE FUEL 6C - 31 INJECTION PUMP ASSEMBLY (4JG2 Belt Drive Type) Removal steps 1. Cooling fan Assembly 2. Fan shroud 3. Power steering pump drive belt 4. A/C compressor drive belt 5. AC generator drive belt 6. Power steering pump & bracket Assembly 7.
  • Page 291 6C - 32 ENGINE FUEL 4. A/C Compressor Drive Belt (A/C Model) • Loosen A/C compressor idler pulley lock nut, adjust bolt, and remove the drive belt. 6C-31-1.tif 5. AC Generator Drive Belt • Loosen AC generator mounting bolt (under side) and adjust plate lock bolt, and remove the drive belt.
  • Page 292 ENGINE FUEL 6C - 33 8. Timing Pulley Upper Cover 9. Timing Pulley Lower Cover 6C-32-1.tif 10. Flange; Camshaft Pulley 6C-32-2.tif 11. Timing Belt • Prepare a fixing bolt (M8 x 40, P=1.25) • Turn crankshaft timing pulley in the normal direct pulley side mark to timing pulley housing side mark.
  • Page 293 6C - 34 ENGINE FUEL 12. Injection Pump Timing Pulley • Install the stopper bolt to the timing pulley to prevent it from turning. 6C-33-1.tif " • Use the timing pulley puller to remove the injection pump timing pulley. Timing Pulley Puller: 5-8840-0086-0 •...
  • Page 294 ENGINE FUEL 6C - 35 INSTALLATION 19. Injection Pump Assembly • Put the timing pulley housing side and injection pump side setting marks together, and temporarily tighten. • After adjusting injection timing retighten. • Mount rear bracket on cylinder block and tighten to the specified torque.
  • Page 295 6C - 36 ENGINE FUEL 13. Air Intake Duct • Connect the air intake duct and tighten clip securely. 12. Injection Pump Timing Pulley • Align the timing pulley with the pump shaft key. • Install the stopper bolt to the timing pulley. This will prevent the timing pulley from moving.
  • Page 296 ENGINE FUEL 6C - 37 • Mount new timing belt on pulleys in the following steps. Crankshaft timing pulley camshaft " Timing pulley. Idle pulley Injection Pump pulley tensioner • Set the belt on crankshaft timing pulley and hold with one hand.
  • Page 297 6C - 38 ENGINE FUEL CAUTION • In case where the timing belt has been replaced with the actuation of warning light, put off the light with change over switch on the reverse side of meter. • Refer to Chassis Electrical in Seetion 8 . •...
  • Page 298 ENGINE FUEL 6C - 39 • Install the Power Steering pump & bracket assembly. 10M bolts N∙m (Kg∙m/lb ft) 40 (4.1/30) 8M bolts N∙m (Kg∙m/lb ft) 19 (1.9/14) Lock nut N∙m (Kg∙m/lb ft) 27 (2.8/20) 5. AC Generator Drive Belt •...
  • Page 299 6C - 40 ENGINE FUEL 3. Power Steering Pump Drive Belt (P/S Model) • Install power steering pump drive belt and adjust belt tension. • Depress the drive belt mid-portion with a 98N (10 kg/22 lb) force. Drive Belt Deflection mm (in) 8 (0.31) - 10 (0.39) •...
  • Page 300 ENGINE FUEL 6C - 41 INJECTION TIMING ADJUSTMENT • Set No. 1 cylinder to top dead center. • Remove injection pump distributor head plug. • Cancel wax CSD with the handle of a screw driver. • Fit a dial gauge and set lift to 2 mm. Measuring device: 5-8840-0145-0 •...
  • Page 301 6C - 42 ENGINE FUEL Adjustment of Idling Speed 1) Pull the parking brake and lock the wheels. 2) Set the transmission gear to the neutral position. 3) Start the engine and idle it until the water temperature gets to 70 to 80°C (158 to176°F). 4) Turn back the idling control button, and remove the control cable from the control lever (injection pump) 5) Set the engine tachometer.
  • Page 302 ENGINE FUEL 6C - 43 INJECTION PUMP DATA TEST CONDITIONS Items Conditions Engine Type 4JB1(Gear) 4JG2(Belt) 4JB1(Gear) 4JG2(Gear) 4JB1TC 4JB1T (For '91/542B) (For '91/542A) (For '91/542A) Euro 2 Euro 1 Euro 1 Injection Nozzle ZEXEL Part Number 105780-0000 105780-0000 105780-0060 105780-0060 105780-0060 ...
  • Page 303 6C - 44 ENGINE FUEL IDENTIFICATION PLATE AND NUMBER Use the data following the injection pump identification number to adjust the injection volume. F06LV002.tif F06LV001.tif F06LW002.tif...
  • Page 304 ENGINE FUEL 6C - 45 INJECTION VOLUME AND GOVERNOR PERFORMANCE DIAGRAM Engine ; 4JB1 Injection pump assembly No. ; 8943616830 (104741-6410) 8943616850 (104741-6430) Adjustment specification of injection volume Average Pump Uneven injection rotation amplitude temperature Remarks quantity °C (38.6) 48±2 34.9±2.5 50±2 1000...
  • Page 305 6C - 46 ENGINE FUEL Engine ; 4JB1 Injection pump identification No. ; 104746-1230, 1240, 1250, 1260, 1280, 1290, 1370 Injection volume adjustment Adjustment specification of injection volume Average Pump Uneven injection rotation amplitude temperature Remarks quantity (rpm) /ST) (°C) /ST) (38.6) 48±2...
  • Page 306 ENGINE FUEL 6C - 47 Engine ; 4JG2 (For ’91/542B) (Belt drive) Injection pump assembly No. ; 897138-8422 (196000-1042) Adjustment specification of injection volume Average Pump Uneven injection rotation amplitude Remarks quantity 78±12 64±6.0 52±3.0 55.9±3.4 1000 62.6±1.0 1250 60.9±3.5 1700 574±3.5 2100...
  • Page 307 6C - 48 ENGINE FUEL Engine ; 4JB1 (For ’91/542A) (Gear drive) Injection pump identification No. ; 104742-1451, 1461, 1471 Injection volume adjustment Adjustment specification of injection volume Average Pump Uneven injection rotation amplitude temperature Remarks quantity (rpm) /ST) (°C) /ST) (29.7±4.5) 48±2...
  • Page 308 ENGINE FUEL 6C - 49 Engine ; 4JB1 (For ’91/542A) (Gear drive) Injection pump identification No. ; 104742-1480, 1490 Adjustment specification of injection Injection volume adjustment volume Average Pump Uneven injection rotation amplitude temperature Remarks quantity (rpm) /ST) (°C) /ST) (29.7±4.5) 48±2 1000...
  • Page 309 6C - 50 ENGINE FUEL Engine ; 4JG2 (For ’91/542A) (Gear drive) Injection pump identification No. ; 104746-1222 Adjustment specification of injection Injection volume adjustment volume Average Pump Uneven injection rotation amplitude temperature Remarks quantity (rpm) /ST) (°C) /ST) (51.6) 48±2 1000 52.0±1.0...
  • Page 310 ENGINE FUEL 6C - 51 Engine ; 4JG2 (For ’91/542A) (Belt drive) Injection pump identification No. ; 104746-1211 Adjustment specification of injection Injection volume adjustment volume Average Pump Uneven injection rotation amplitude temperature Remarks quantity (rpm) /ST) (°C) /ST) (53.7) 48±2 1000 56.0±1.0...
  • Page 311 6C - 52 ENGINE FUEL Engine ; 4JB1T Injection pump identification No. ; 104746-6311, 104746-6380 Injection volume adjustment Adjustment specification of injection volume Average Boost Pump Uneven injection pressure rotation amplitude temperature Remarks quantity (kPa (rpm) /ST) (°C) /ST) (kg/cm (37.0±4.0) —...
  • Page 312 ENGINE FUEL 6C - 53 Engine ; 4JB1T Injection pump identification No. ; 104746-6670 Injection volume adjustment Adjustment specification of injection volume Average Boost Pump Uneven injection pressure rotation amplitude temperature Remarks quantity (kPa (rpm) /ST) (°C) /ST) (kg/cm (33.9±4.0) —...
  • Page 313 6C - 54 ENGINE FUEL Engine ; 4JB1TC Injection pump identification No. ; 104746-6601 Injection volume adjustment Adjustment specification of injection volume Average Boost Pump Uneven injection pressure rotation amplitude temperature Remarks quantity (kPa (rpm) /ST) (°C) /ST) (kg/cm 60.5±1.0 48±2 Standard 67.4±1.0...

  • Page 314: Fuel Tank

    ENGINE FUEL 6C - 55 FUEL TANK 6C-54-1.tif REMOVAL Preparation: • Disconnect battery ground cable. • Loosen fuel filler cap. • Drain fuel from drain plug. • After the drain fuel, tighten the drain plug to the specified torque. N∙m (Kg∙m/lb∙ft) 29 (3/22) 1.
  • Page 315 6C - 56 ENGINE FUEL 6. Fuel Tank • Pull out the fuel tank to the outside. Note: When it is not possible to pull out the fuel tank, remove the bracket and then draw out the fuel tank downward. INSTALLATION 6.
  • Page 316 ENGINE FUEL 6C - 57 FUEL GAUGE UNIT 6C-56-1.tif REMOVAL Preparation: Disconnect Battery ground cable. 1. Fuel Gauge Unit Connector • Disconnect fuel gauge unit connector from fuel gauge unit. 2. Fuel Gauge Unit • Remove fuel gauge unit fixing screw and fuel gauge unit.
  • Page 317 6C - 58 ENGINE FUEL ACCELERATOR CONTROL ACCELERATOR CONTROL CABLE 6C-57-1.tif REMOVAL 1. Adjust Nut • Loosen the adjust nut on the cable bracket mounted on the inlet manifold. 2. Accelerator Control Wire (Injection Pump Side) • Remove the control wire from injection pump control lever.
  • Page 318 ENGINE FUEL 6C - 59 INSPECTION Check the following items, and replace the control cable if any abnormality is found. • The control cable should move smoothly. • The control cable should not be bent or kinked. • The control cable should be free of damage and corrosion.
  • Page 319 6C - 60 ENGINE FUEL ACCELERATOR PEDAL 6C-59-1.tif REMOVAL 1. Idle Switch Connector 2. Accelerator Control Cable • Remove control cable from Accelerator pedal bracket. 3. Idling Control Cable • Remove control cable from accelerator pedal bracket. 4. Accelerator Pedal Assembly •...
  • Page 320 ENGINE FUEL 6C - 61 Adjustment of the press-down amount of the accelerator pedal • After installing each cable, give a full stroke to the accelerator pedal while pushing the accelerator pedal pad by hand. • Adjust the stopper bolt so that the clearance between the pedal pad stopper bolt and the back of the pad becomes 0 ~ 2 mm (0 ~0.079 in.), and tighten the lock nut to the specified torque.
  • Page 321 6C - 62 ENGINE FUEL IDLING CONTROL CABLE 6C-61-1.tif REMOVAL 1. Idling Control Knob • Loosen the idling control knob screw and remove the knob from cable. 2. Idling Control Cable Nut 3. Wave Washer 4. Idling Control Cable • Remove control cable from accelerator pedal bracket.
  • Page 322 ENGINE FUEL 6C - 63 1. Idling Control Knob • Insert the idling control knob into the cable, and tighten the screw. Inspection: • With the idling control knob not in use, check to see if the injection pump lever is at the idle position (with the lever in contact with the stopper bolt).
  • Page 323 6C - 64 ENGINE FUEL AIR CLEANER ELEMENT 6C-63-1.tif REMOVAL 1. Cover Wing Nut 2. End Cover 3. Filter Wing Nut 4. Air Cleaner Element Clean • Wipe out the inside of the Air Cleaner assembly. • Wipe off the Cover Inspection •...
  • Page 324 ENGINE FUEL 6C - 65 Carbon and Dust Fouled Element 1. Prepare a cleaning solution of Isuzu Genuine Element Cleaner (Donaldson D1400) diluted with water. 2. Submerge the element in the solution for twenty minutes. 6C-64-1.tif 3. Remove the element from the solution and rinse it well with running water.
  • Page 325 6C - 66 ENGINE FUEL MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

  • Page 326: Engine Electrical

    HOME ENGINE ELECTRICAL 6D1 – 1 SECTION 6D ENGINE ELECTRICAL CONTENTS PAGE Battery ........................... Starting System ......................Charging System ......................QOS-II Preheating System ................... QOS-III Preheating System ..................SECTION 6D1 BATTERY CONTENTS PAGE General Description...................... 6D1-2 Diagnosis........................6D1-2 On-Vehicle Service ....................... 6D1-4 Battery Charging.......................
  • Page 327 6D1 – 2 ENGINE ELECTRICAL GENERAL DESCRIPTION There are six battery fluid caps at the top of the battery. The battery protects itself against overcharging. these are covered by a paper label. The battery will refuse to accept an excessive charge.
  • Page 328 ENGINE ELECTRICAL 6D1 – 3 4. LOAD TEST (1) Connect a voltmeter and a battery load tester across the battery terminals. (2) Apply 300 ampere load for 15 seconds to remove surface charge from the battery. Remove load. (3) Wait 15 seconds to let battery recover. Then apply specified load from specifications (See Main Data and Specifications in this section).

  • Page 329: Battery Charging

    6D1 – 4 ENGINE ELECTRICAL ON-VEHICLE SERVICE BATTERY CHARGING Observe the following safety precautions when charging the battery: 1. Never attempt to charge the battery when the fluid level is below the lower level line on the side of the battery.
  • Page 330 ENGINE ELECTRICAL 6D1 – 5 JUMP STARTING JUMP STARTING WITH AN AUXILIARY (BOOSTER) BATTERY CAUTION: Never push or tow the vehicle in an attempt to start it. Serious damage to the emission system as well as other vehicle parts will result. Treat both the discharged battery and the booster battery with great care when using jumper cables.
  • Page 331 6D1 – 6 ENGINE ELECTRICAL JUMP STARTING PROCEDURE 1. Set the vehicle parking brake. If the vehicle is equipped with an automatic transmission, place the selector lever in the "PARK" position. If the vehicle is equipped with a manual transmission place the shift lever in the "NEUTRAL"...
  • Page 332 ENGINE ELECTRICAL 6D1 – 7 WARNING: Never attach the end of the jumper cable directly to the negative terminal of the dead battery. 5. Start the engine of the vehicle with the good battery. Make sure that all unnecessary electrical accessories have been turned "OFF".
  • Page 333 6D1 – 8 ENGINE ELECTRICAL MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

  • Page 334: Starting Circuit

    STARTING SYSTEM 6D2 – 1 SECTION 6D2 STARTING SYSTEM CONTENTS PAGE General Description....................... 6D2 - 1 On-Vehicle Service ....................6D2 - 3 Unit Repair........................6D2 - 5 GENERAL DESCRIPTION STARTING CIRCUIT The cranking system consists of a battery, starter, components are connected as shown in Figure. For starter switch, starter relay, etc.
  • Page 335 6D2 – 2 STARTING SYSTEM STARTING CIRCUIT 6D2-2-1.tif...
  • Page 336 STARTING SYSTEM 6D2 – 3 ON-VEHICLE SERVICE 6D2-3-1.tif REMOVAL Preparation • Disconnect Battery Ground Cable. 1. "50" Terminal 2. "30" Terminal 3. Earth Cable Terminal 4. Starter Assembly 5. Spacer (4JB1, Except cold area) 6D2-3-2.tif INSTALLATION 5. Spacer (4JB1, Except cold area) 4.
  • Page 337 6D2 – 4 STARTING SYSTEM 2. "30" Terminal • Connect the harness connector. 1. "50" Terminal • Connect the battery cable terminal with starter switch harness terminal, then tighten nut to the specified torque. Fixing Nut Torque N∙m (Kg∙m/lb∙in) 9 (0.9/78) •...
  • Page 338 STARTING SYSTEM 6D2 – 5 UNIT REPAIR 6D2-5-1.tif DISASSEMBLY 1. Lead Wire Disconnect the lead wire from the magnetic switch. 6D2-5-2.tif 2. Through Bolt Remove the through bolts from the yoke. 6D2-5-3.tif...
  • Page 339 6D2 – 6 STARTING SYSTEM 3. Yoke Assembly Separate the yoke from the solenoid switch. 4. Yoke Cover 6D2-6-1.tif 5. Brush and Brush Holder Remove (pull out) the brushes and the brush holder from the armature with a pair of long-nose pliers. 6.
  • Page 340 STARTING SYSTEM 6D2 – 7 8. Overrunning Clutch Remove the overrunning clutch from the housing. 6D2-7-1.tif 9. Return Spring Remove the return spring from magnetic switch. 6D2-7-2.tif 10. Steel Ball Remove the steel ball from the overrunning clutch. 6D2-7-3.tif 11. Idle Pinion Remove the idle pinion from housing.
  • Page 341 6D2 – 8 STARTING SYSTEM INSPECTION AND REPAIR Make necessary correction or parts replacement if wear, damage or any other abnormal condition are found through inspection. ARMATURE Check the commutator for run-out and replace if the amount of run-out exceeds the limit. Run-out test mm (in.) Standard...
  • Page 342 STARTING SYSTEM 6D2 – 9 Armature ground test Touch one probe of a circuit tester to the commutator segment and the other to the armature core. There should be no continuity. If there is a continuity, the armature is grounded. Replace the armature if it is grounded.

  • Page 343: Overrunning Clutch

    6D2 – 10 STARTING SYSTEM BRUSH AND BRUSH HOLDER Measure the brush length and replace if it is worn beyond the service limit. Brush length mm (in.) Standard Limit 14.5 (0.57) 10 (0.39) 16 (0.63) 6D2-10-1.tif Brush holder insulation test Using a circuit tester, check the brush holder insulation.
  • Page 344 STARTING SYSTEM 6D2 – 11 REASSEMBLY To install, follow the removal steps in the reverse order, noting the following points: • Magnetic Switch • Idle Gear • Clutch assembly • Housing 1) Install the clutch asm to the magnetic switch. 2) Install the idle gear and housing.
  • Page 345 6D2 – 12 STARTING SYSTEM MAGNETIC SWITCH Temporarily connect the solenoid switch between the clutch and the housing and run the following tests. Complete each test within three to five seconds. 1. Pull-in test Connect the battery negative terminal with the solenoid switch body and the M terminal.
  • Page 346 CHARGING SYSTEM 6D3 – 1 SECTION 6D3 CHARGING SYSTEM CONTENTS PAGE General Description....................... 6D3 - 1 Diagnosis........................6D3 - 4 On-Vehicle Service ......................6D3 - 5 Unit Repair........................6D3 - 9 GENERAL DESCRIPTION The charging system is the IC integral regulator The generator does not require particular maintenance charging system and its main components are such as voltage adjustment.
  • Page 347 6D3 – 2 CHARGING SYSTEM Generator 6D3-2-1.tif 6D3-2-2.tif...

  • Page 348: Charging Circuit

    CHARGING SYSTEM 6D3 – 3 CHARGING CIRCUIT 6D3-3-1.tif...
  • Page 349 6D3 – 4 CHARGING SYSTEM DIAGNOSIS GENERAL ON-VEHICLE INSPECTION The operating condition of charging system is indicated by the charge warning lamp. The warning lamp comes on when the starter switch is turned on "ON" position. The charging system operates normally if the lamp goes off when the engine starts.
  • Page 350 CHARGING SYSTEM 6D3 – 5 ON-VEHICLE SERVICE GENERATOR 6D3-5-1.tif REMOVAL Preparation • Disconnect battery ground cable. 1. A/C Compressor Drive Belt (A/C Model) • Loosen the idler pulley lock nut • Loosen the adjust bolt and remove the drive belt. 2.
  • Page 351 6D3 – 6 CHARGING SYSTEM 3. Harness Connector (A/C Model) • Disconnect the "L", "S", "IG" terminal. • Disconnect the "B" terminal. 4. Vacuum Hose (EXH. Brake Model) • Remove the vacuum hose to vacuum tank and exhaust actuator. 5. Oil Hose •...
  • Page 352 CHARGING SYSTEM 6D3 – 7 • Install the suction pipe clip bolt and tighten bolt to the specified torque. Pipe Clip Bolt torque N∙m (kg∙m/lb∙in) 10 (1.0/87) • Install the pressure pipe and suction pipe clip bolt, then tighten bolt to the specified torque. Pipe Clip Bolt Torque N∙m (kg∙m/lb∙in) 10 (1.0/87)
  • Page 353 6D3 – 8 CHARGING SYSTEM 2. A/C compressor Assembly (A/C Model) • Install the compressor assembly and tighten bolts to the specified torque. Compressor Bolt Torque N∙m (kg∙m/lb∙ft) 19 (1.9/14) • Connect the magnetic switch harness connector. 6D3-8-1.tif 1. A/C compressor Drive Belt (A/C Model) •...
  • Page 354 CHARGING SYSTEM 6D3 – 9 UNIT REPAIR 6D3-9-1.tif DISASSEMBLY 1. Vacuum Pump • Dram fluid from discharged port. • Remove the vacuum pump fixing bolts. Hold the center plate and remove the vacuum pump horizontally in direction in line with the rotor shaft. 2.
  • Page 355 6D3 – 10 CHARGING SYSTEM 6. Rotor • With the rotor gripped with a vise, remove the pulley " , and then take off the pulley , fan , front cover and the rotor 6D3-10-1.tif 7. Rear Bearing 8. Terminal Bolt and Nut 9.
  • Page 356 CHARGING SYSTEM 6D3 – 11 ROTOR 1. Check the rotor slip ring surfaces for contamination and roughness. If rough, polish with #500-600 sandpaper. 2. Measure the slip ring diameter, and replace if it exceeds the limit. mm (in) Standard Limit 34.6 (1.36) 33.6 (1.32) 6D3-11-1.tif...
  • Page 357 6D3 – 12 CHARGING SYSTEM 2. Check for continuity across one of the stator coils and stator core. If a continuity exists, replace the coil. 6D3-12-1.tif DIODE 1. Check for continuity across the terminal (example: across BAT and U). If a continuity exists, the diode is in satisfactory condition.
  • Page 358 CHARGING SYSTEM 6D3 – 13 IC REGULATOR Measuring instruments is necessary. Take the following measurements with the instruments connected as shown in the illustration. V1 Voltage at BAT1 Standard 10 - 13 V2 Voltage across F-E Standard Limit 2 or less 2 or more Take measurement with `S' terminal disconnected.

  • Page 359: Vacuum Pump

    6D3 – 14 CHARGING SYSTEM VACUUM PUMP Visual check • Inspect the following parts for wear, damage or other abnormal conditions. Disassembly of Vacuum pump • For the center plate, rotor and vane in the mentioned. 6D3-14-1.tif Housing • Measure the inside diameter of housing and place if it exceed the standard.
  • Page 360 CHARGING SYSTEM 6D3 – 15 REASSEMBLY 13. Brush Holder 12. IC Regulator Assembly • Hold the brush in the holder as shown in the illustration and solder the lead wire. • Put the IC regulator on the brush holder and press the bolt.
  • Page 361 6D3 – 16 CHARGING SYSTEM 5. Stator and Rear Cover Assembly 4. Rotor and Front Cover Assembly 3. Through Bolts • Place guide bar through the holes in front cover and rear cover flange for alignment, then install the through bolts.
  • Page 362 CHARGING SYSTEM 6D3 – 17 UNIT REPAIR 6D3-17-1.tif DISASSEMBLY 1. Removal of Through Bolts Remove the three through bolts. 6D3-17-2.tif 2. Separation of Drive End Frame and Rear End Frame & Stator As illustrated, put a screw-driver into the notched part of the drive end frame and separate the rear end frame and stator from the drive end frame.
  • Page 363 6D3 – 18 CHARGING SYSTEM 3. Separation of Pulley, Fan, Drive End Frame, and Rotor Fix the rotor in a lock vice, and after removing the lock nut separate the pulley, fan, drive end frame, and rotor. NOTE: Be sure to fix the rotor through cloth in a vice. 6D3-18-1.tif 4.
  • Page 364 CHARGING SYSTEM 6D3 – 19 Tighten the lightly with 7. Removal of Bearing (on the Rear Side) [Only for a vise with care not to Replace.] cause any damage Take out the bearing with a puller. Insert it to see whether replacement is needed. NOTE: Conduct the bearing inspection mentioned below and determine whether or not the bearing be replaced.
  • Page 365 6D3 – 20 CHARGING SYSTEM In this case, the slip ring can be used until its outer diameter becomes 0.4mm shorter than the initial size. 6D3-20-1.tif 5) Rectifier Conduct a rectifier continuity test using the KΩ range of a circuit tester. Specifically, change polarity between the rectifier and holder fin, making sure that there continuity in either one direction only.
  • Page 366 CHARGING SYSTEM 6D3 – 21 REASSEMBLY Follow the same procedure as for disassembly in the opposite order, paying special attention to the following points: • Brush When fitting a new brush, be sure to see it so that the free end of it is projecting 12.5mm (0.49 in) from the holder.
  • Page 367 6D3 – 22 CHARGING SYSTEM MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
  • Page 368 QOSII PREHEATING SYSTEM 6D6 – 1 SECTION 6D6 QOSII PREHEATING SYSTEM (4JB1/4JB1T/4JB1TC ONLY) CONTENTS PAGE General Description....................... 6D6 - 1 System Diagram......................6D6 - 2 Inspection on QOS II system Operation ..............6D6 - 3 QOSII System Troubleshooting..................6D6 - 4 GENERAL DESCRIPTION QOS II preheating system features a quick-on glow With the employment of the thermoswitch, the glow...
  • Page 369 6D6 – 2 QOSII PREHEATING SYSTEM SYSTEM DIAGRAM 6D6-2-1.tif QOS II Timing Chart 6D6-2-2.tif...

  • Page 370: Glow Plug

    QOSII PREHEATING SYSTEM 6D6 – 3 Inspection on QOSII System Operation THERMO SWITCH The thermo switch is located on the water outlet pipe. 6D6-3-1.tif Use a circuit tester to check the thermo switch for continuity. OFF!ON : 7-13°C (44.6-55.4°F) ON!OFF : Below 3°C (37.4°F) 10°C 3°C...
  • Page 371 6D6 – 4 QOSII PREHEATING SYSTEM QOSII SYSTEM TROUBLESHOOTING 6D6-4-1.tif Problems when the water temperature of the engine is 0°C below. Condition Cause Circuit Glow plug relay will Bad connection of FLW between battery and starter. not be lit. Bad connection or disconnection of starter SW circuit Bad connection or disconnection Malfunction of other of Fuse No .
  • Page 372 QOSII PREHEATING SYSTEM 6D6 – 5 Condition Cause Circuit Through glow plug Bad connection of FLW between battery and glow relay. relay turns ON, Bad connection or disconnection in preheating circuit of glow relay main contact preheating is not terminal connector. done.
  • Page 373 6D6 – 6 QOSII PREHEATING SYSTEM MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
  • Page 374 QOSIII PREHEATING SYSTEM 6D7 – 1 SECTION 6D7 QOSIII PREHEATING SYSTEM (4JG2 ONLY) CONTENTS PAGE General Description....................... 6D7 - 1 System Diagram......................6D7 - 2 Inspection on QOS III system Operation ..............6D7 - 5 GENERAL DESCRIPTION QOS III preheating system features a quick-on glow With the employment of the thermoswitch, the glow plug with thermometer control of the glowing time and time changes according to the engine coolant...
  • Page 375 6D7 – 2 QOSIII PREHEATING SYSTEM SYSTEM DIAGRAM 6D7-2-1.tif QOS II Timing Chart 6D7-2-2.tif...
  • Page 376 QOSIII PREHEATING SYSTEM 6D7 – 3 QOS III FLOW CHART 6D7-3-1.tif...
  • Page 377 6D7 – 4 QOSIII PREHEATING SYSTEM QOS III BLOCK CHART 6D7-4-1.tif...
  • Page 378 QOSIII PREHEATING SYSTEM 6D7 – 5 Inspection on QOSIII System Operation Inspection on Quick Heating Operation 1. Disconnect thermo-sensor connection on the thermostat housing. 6D7-5-1.tif 2. Connect the circuit tester between glow plug and engine earth. 3. Inspect the following items with starter switch set to ON position (but do not start the engine).
  • Page 379 6D7 – 6 QOSIII PREHEATING SYSTEM 2. Connect the circuit tester between glow plug and engine earth. 3. Inspect the following items with start the engine. 1) The circuit tester shall indicate about 7 volts after 360 seconds of engine start. •...
  • Page 380 QOSIII PREHEATING SYSTEM 6D7 – 7 DROPPING RESISTOR Inspect the resistance Resistance of normal ambient temperature mΩ 225 ~ 255 6D7-7-1.tif GLOW PLUG RELAY Inspect the continuity " No Continuity If apply the battery voltage to terminal between " Continuity 6D7-7-2.tif CHARGE RELAY Inspect the continuity...
  • Page 381 6D7 – 8 QOSIII PREHEATING SYSTEM MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

  • Page 382: Exhaust Gas Recirculation (Egr) System

    HOME EXHAUST GAS RECIRCULATION (EGR) SYSTEM 6E– 1 SECTION 6E EXHAUST GAS RECIRCULATION (EGR) SYSTEM CONTENTS PAGE General Description......................6E -2 EGR System Wiring Diagram.................... 6E -3 EGR System Operation ..................... 6E -3 EGR System Check ......................6E -4 Inspection........................... 6E -5...
  • Page 383 6E – 2 EXHAUST GAS RECIRCULATION (EGR) SYSTEM GENERAL DESCRIPTION D06LX001.tif This system controls the formation of NOx emission by recirculating the exhaust gas into the combustion chamber through the intake manifold. The EGR valve are controlled by VSV, also VSV are controlled by EGR controller according to signals from RPM sensor and Potentiometer.
  • Page 384 EXHAUST GAS RECIRCULATION (EGR) SYSTEM 6E– 3 EGR SYSTEM WIRING DIAGRAM (above 40 : OFF) (below 30 : ON) 826LX007.tif 1. CONNECTOR PIN ASSIGNMENT CONNECTOR NAME Battery (-) c/u GND Thermo Switch Battery (+) rpm Signal (+) rpm Signal (-) Potentio Meter (+) 13-01.tif Potentio Meter...
  • Page 385 6E – 4 EXHAUST GAS RECIRCULATION (EGR) SYSTEM Exhaust Gas Recirculation (EGR) System Check Step Action Value (s) Check the EGR valve for looseness. Go to Step 2 Go to Step 3 Is the EGR valve loose? Tighten the EGR valve. Verify repair Is the action complete? 1.
  • Page 386 EXHAUST GAS RECIRCULATION (EGR) SYSTEM 6E– 5 INSPECTION Vacuum Switch Valve (VSV) Check the resistance between the VSV connector terminals using a circuit tester. Cold Resistance: 37 - 44 (Ω) (for 12 volt) Connect battery voltage between VSV connector terminals and make sure of the continuity between the ports.
  • Page 387 6E – 6 EXHAUST GAS RECIRCULATION (EGR) SYSTEM MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

  • Page 388: Engine Exhaust

    HOME ENGINE EXHAUST 6F – 1 SECTION 6F ENGINE EXHAUST CAUTION: Exhaust system components must have enough of the floor pan and possible damage to the passenger clearance from the underbody to prevent overheating compartment, insulation and trim materials. CONTENTS PAGE General Description......................
  • Page 389 6F – 2 ENGINE EXHAUST GENERAL DESCRIPTION Model ’91/542B (Euro 2) 501LX002.tif General Export 501LX003.tif When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.
  • Page 390 ENGINE EXHAUST 6F – 3 THREE WAY CATALYTIC CONVERTER The three way catalytic converter is an emission control device added to the exhaust system to reduce pollutants from the exhaust gas stream. CAUTION: • The catalytic converter requires the use of unleaded fuel only.
  • Page 391 6F – 4 ENGINE EXHAUST ON-VEHICLE SERVICE Rattles and noise vibrations in the exhaust system are usually caused by misalignment of parts. When aligning the system, leave all bolts or nuts loose until all parts are properly aligned; then tighten, working from front to rear. 1.
  • Page 392 ENGINE EXHAUST 6F – 5 INSTALLATION 4. Front exhaust pipe. 3. Front exhaust pipe fixing bolts and nuts. • Tighten the fixing nuts to the specified torque N∙m (kg∙m/lb∙ft) 50 (5.1/37) 2. Front exhaust pipe mounting bracket fixing bolt and nut. •...
  • Page 393 6F – 6 ENGINE EXHAUST MEMO ..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
  • Page 394 HOME TURBOCHARGER 6G – 1 SECTION 6G TURBOCHARGER CONTENTS PAGE Turbocharger ........................6G - 2 Main Data and Specifications ..................6G - 2 General Description......................6G - 3 Identification of Unit....................6G - 4 Turbocharger Servicing ....................6G - 4 Precautions ........................
  • Page 395 6G – 2 TURBOCHARGER TURBOCHARGER MAIN DATA AND SPECIFICATIONS Model IHI RHF 4H IHI RHB 5 Turbine type Mixed-flow Radial-inflow Compressor type Centrifugal Maximum permissible speed 180,000 Wastegate opening pressure kPa (mmHg) 109 ± 4.4 (815 ± 33) 120 ± 4.8 (898 ± 36) Weight N (kg/lb) 41 (4.2/9.3)
  • Page 396 TURBOCHARGER 6G – 3 GENERAL DESCRIPTION 6G-3-1.tif The turbocharger internal mechanism consists of the turbine wheel, the compressor wheel, and the radial bearings. These parts are supported by the bearing housing. The turbocharger external mechanism consists of the compressor housing air intake port and the turbine housing air exhaust port.
  • Page 397 Faulty turbocharger servicing procedures can result in serious damage to pistons, valves, cylinder liners, and other important engine parts. ISUZU does not recommended the performance of any servicing procedure not specified described in this Manual. Contact your nearest IHI service facility to have the turbocharger assembly repaired or overhauled.
  • Page 398 TURBOCHARGER 6G – 5 DISASSEMBLY 036LW001.tif Disassembly Steps Bolt Compressor housing Turbine housing Center housing and rotating assembly Bolt...
  • Page 399 6G – 6 TURBOCHARGER Disassembly Steps 1. Bolt Apply a setting mark across the center housing and rotating assembly (1), the turbine housing (2), and the compressor housing (3). 6G-6-1.tif 2. Turbine Housing 3. Bolt 4. Compressor Housing 5. Center Housing and Rotating Assembly 1) Loosen the bolts.
  • Page 400 TURBOCHARGER 6G – 7 INSPECTION AND REPAIR Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during inspection. Minor servicing operations are described in this Section. Contact the nearest IHI SERVICE FACILITY for major repairs and maintenance.
  • Page 401 6G – 8 TURBOCHARGER Important wheel shaft end play and bearing clearance standards and limits are included below for your reference. Wheel Shaft End Play Use a dial indicator to measure the wheel shaft end play. Apply a force of 1.2 kg (2.6 lb/11.8N) alternately to the compressor wheel end and the turbine wheel end.
  • Page 402 TURBOCHARGER 6G – 9 REASSEMBLY 036LW002.tif Reassembly Steps Center housing and rotating assembly Turbine housing Compressor housing Bolt Bolt...
  • Page 403 6G – 10 TURBOCHARGER Reassembly Steps 1. Center Housing and Rotating Assembly 2. Compressor Housing 3. Bolt 1) Apply Threebond 1215 or equivalent to flange surface of compressor housing shown in the illustration. 2) Align the setting marks (applied at disassembly) on the center housing and rotating assembly and the compressor housing.
  • Page 404 TURBOCHARGER 6G – 11 IHI SERVICE NETWORK For inquiries relating to turbochargers, please contact your ISUZU distributor or the nearest IHI Turbocharger Service Facility. HEADQUARTERS ISHIKAWAJIMA HARIMA HEAVY INDUSTRIES CO., LTD.(IHI) General Machinery Division Tokyo Chuo Building 1-6-2 Marunouchi Chiyoda-ku...
  • Page 405 This manual is applicable for vehicles in all countries except the USA and Canada. All rights reserved. This manual may not be reproduced in whole or in part, without the permission in writing of ISUZU MOTORS LIMITED. Issued by ISUZU MOTORS LIMITED INTERNATIONAL SERVICE DEPARTMENT Tokyo, Japan First edition Jan., 1999...
  • Page 406 No. HGSTG-WE-661 PRINTED IN JAPAN...

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