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Related Manuals for Opel 1991 Astra
Summary of Contents for Opel 1991 Astra
- Page 1 Electronic Workshop Manual...
- Page 381 T.B.I. Manual...
- Page 1025 Developed by Derek Naidoo..10.97...
- Page 1026 Gas Analysis Diagnostics using a 4 Gas Analyser Before attempting to perform any diagnostics using a 4 gas analyser, it is important to understand the equipment and the results obtained. We shall begin with explaining the different gases tested : Hydrocarbons (HC) Hydrocarbons are unburned or partially burnt fuel particles.
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Page 1027: Carbon Monoxide
Air: Fuel Ratio and Gas Emission Theory HC and CO Analysis Hydrocarbons The ignition of the air : fuel mixture in the combustion chamber does not result in all the fuel being burned, hence the HC emmission. Should there be any malfunction in the system the quantity of Hc will increase. - Page 1028 CO2 and O2 Analysis Carbon Dioxide Carbon dioxide is a product of combustion. A normal functioning engine should produce between 13 and 16 % of CO2. If combustion was incomplete or the air : fuel ratio was incorrect, the quantity of CO2 produced will be minimised resulting in a less efficient engine.
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Page 1029: Possible Cause
Diagnostics Condition Possible Cause (Conventional and Electronic Management Systems) - Page 1031 Injection Systems Multi Point Simultaneous Injectors receive pulses from E.C.U. twice per engine cycle. ( Corsa 13 NE, 16NE, Astra 14SE, 16SE, 18XE, 20SHE ) Sequential Injectors are pulsed by E.C.U. once per engine cycle as per spark plug firing order. ( Astra 20XE ) Grouped Injectors pulsed in groups or banks, once or twice per cycle depending on system design...
- Page 1032 TESTING INFORMATION AND TEST PROCEDURES Typical Simultaneous Injection Duration Engine Cold Cranking ------------------------------------------ >4 Idle -------------------------------------------3.5 to 4 Engine Warm Idle --------------------------------------------- 1000rpm 2.3* * Gradually leans out, 2000 2.1* depending on load 3000 2.0* Snap Throttle >7 Sequential injection systems will be less than twice the above values due to single pulsing per engine cycle.
- Page 1033 DUPEC ELECTRONICS (PTY) LTD DEFITA200 MICROCONTROLLER BASED FUEL INJECTION AND SPARK TIMING SYSTEM AND INTERFACE SPECIFICATION TRAINING MANUAL 93/5...
- Page 1034 CONTENTS PRODUCT DESCRIPTION FEATURES PRODUCT IDENTIFICATION AND APPLICATION SPECIFICATION Electrical Environmental Fuel delivery CONNECTIONS SPARK TIMING Distributor bypass operation Engine speed and crankshaft position measurement Engine load measurement Advance angle look-up Ignition firing delay calculation Dwell time calculation Engine water temperature measurement FUEL INJECTION Air mass to fuel mass ratio Air mass measurement...
- Page 1035 7.9.9 Coasting conditions 7.9.10 Flooded engine conditions 7.9.11 Full load operation IDLE SPEED IMMOBILISER OPERATION 10.0 DEFAULT MODE SELECTION 11.0 DIAGNOSTICS 11.1 Diagnostic codes 11.2 Volt- and ohmmeter 11.2.1 Battery voltage 11.2.2 Ignition voltage 11.2.3 TPS supply voltage 11.2.4 TPS input signal voltage 11.2.5 CO potentiometer supply voltage 11.2.6...
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Page 1036: Product Description
PRODUCT DESCRIPTION The DEFITA200 range of ECU's (Engine Control Units) is microcontroller based and controls the spark timing, fuel injection and certain other functions of internal combustion engines electronically, thus ensuring optimum operating efficiency. DEFITA200 is an abbreviation for Dupec Electronic Fuel Injection and Timing Advance. - Page 1037 - User selectable spark timing curves for different fuel octane ratings - User selectable fuel mixture maps for different octane ratings - Automatic default mode selection in the event of sensor failure allows limp-home operation - Air-conditioner shutdown control - Self-diagnostics with fault storage - Intelligent PC based diagnostics with logging facility.
- Page 1038 PRODUCT IDENTIFICATION AND APPLICATION The product is identified by a white label on its lid having the following information. (P/N93593652 supersedes 93591117) DEFITA200 160 TBi MODEL NO.: A020-C DMC P/N: 93593652 MADE IN R.S.A.
- Page 1039 SPECIFICATION The following specification is applicable to DEFITA200 P/N: A020-C ECU's unless otherwise stated: 4.1 Electrical Operating voltage : 9 to 15 VDC continuous : 6 to 16 VDC limited functions : 24 VDC for 60 seconds maximum Operating current : Less than 500 mA Standby current : Less than 12 mA (>1 minute after ignition off) Timing accuracy : +/- 0.5 degrees...
- Page 1040 Fuel mixture adjustment : - 15% Leaner : - 10% Leaner : - 05% Leaner : + 05% Richer : + 10% Richer : + 15% Richer : + 20% Richer : + 25% Richer Selectable by installing optional mixture selection plug. Operation only possible in open throttle position.
- Page 1041 Fuel pump prime time : 2 +/- 0.2 seconds Immobiliser arming : Automatic; de-arming after success- ful communication with the ACU Protection : All input and output terminals are protected against accidental shorts to ground or battery voltage except the following :- diagnostic lamp to 12 volt - coil drive to 12 volt Default mode selection : Automatic in the event of a...
- Page 1042 CONNECTIONS All input and output connections are made via a 48-pin AMP connector. TERMINAL NO. DESIGNATION ----------------------------------------------------------------- - NC (no connection) - NC - NC - NC - NC - Diagnostics initialise input - A/C switch input signal - A/C clutch input signal (not used) - Rev.
- Page 1043 - Phase 1D drive signal to stepper motor terminal D - Phase 1C drive signal to stepper motor terminal C - Phase 2B drive signal to stepper motor terminal B - Phase 2A drive signal to stepper motor terminal A - TPS input signal from terminal C - Bypass signal to distributor terminal C - Coil driver output signal to distributor...
- Page 1044 SPARK TIMING Spark timing and fuel injection for DEFITA200 ECU's is calculated by a central processing unit and are based on: I - MAP II - EWT III - Battery voltage IV - Crankshaft position V - Engine speed VI - Throttle position The optimum timing advance curves for a given engine are determined by running the engine on an engine dynamometer under any combination of the above-mentioned conditions.
- Page 1045 6.1 Distributor bypass operation At engine speeds below 450 r.p.m. the ECU does not control the firing angle. The ECU keeps the bypass line to terminal C of the distributor low for engine speeds below 450 r.p.m. The spark advance for the vehicle is set to 10ø BTDC by the distributor, while the engine speed is below 450 r.p.m..
- Page 1046 6.3 Engine load measurement Engine load is measured by an external MAP ( Manifold Abso- lute Pressure) sensor. Absolute pressure measurement auto- matically adjust spark timing for altitude changes. It is also required to determine the air mass for fuel injection applications.
- Page 1047 6.5 Ignition firing delay calculation The advance angle obtained from the look-up matrix is sub- tracted from the 10ø BTDC marker on the distributor shaft to obtain the firing angle delay. Example: Advance angle = -20ø on next cycle Marker position = -10ø...
- Page 1048 6.6 Dwell time calculation Dwell time is the time during which the battery voltage must be applied to the ignition coil's primary winding prior to an ignition pulse. The correct dwell time is important to ensure constant spark energy. The correct dwell time depends on the battery voltage. A look-up matrix contains dwell time versus battery voltage.
- Page 1049 FUEL INJECTION It is the function of any fuel injection system to ensure that the correct mass ratio of air and fuel is delivered to the engine under all operating conditions. We will concen- trate on TBi (Throttle Body Injection or alternatively called single point fuel injection systems) in this docu- ment.
- Page 1050 7.1 AIR MASS TO FUEL MASS RATIO The theoretical air mass to fuel mass ratio required by an internal-combustion engine for complete combustion is 14.7:1. This ratio is also called the stoichiometric ratio. The A/F ratio determines the fuel consumption, maximum engine power output and exhaust gas emission levels.
- Page 1051 7.2 AIR MASS MEASUREMENT As we have seen previously the principle of fuel injection is based on measuring the air mass entering the engine and calculating the fuel mass required to obtain an A/F ratio of 14.7:1. A number of possible methods exist for measuring the air mass, but only the speed-density method used for this TBi system will be described in detail.
- Page 1052 7.3 SPEED DENSITY CONCEPT If we know the density of the air inside a container it is possible to calculate the exact mass of the air inside the container. Am = Va*p Where Am = Air mass (g) Va = Air volume (cc) p = Air density (g/cc) In an automotive FI application the quantity of fuel to be injected can be calculated if the displacement volume of the...
- Page 1053 Volumetric efficiency depends mainly on the: a) Inlet valve and camshaft design b) Inlet manifold design c) Engine speed The volumetric efficiency is normally less than one (1) and has the effect that the actual air mass entering the cylin- der will be less than the measured value.
- Page 1054 7.5 CONTINUOUS FUEL FLOW RATE The continuous fuel flow rate at a constant battery voltage is dependent on the injector design, fuel pump and fuel pressure used. Tests have shown that the fuel flow rate, for the Rochester TBi system, is dependent on the applied battery voltage.
- Page 1055 The injector drive circuit allows a pull-in current of 4A and a holding current of 1A. Once an injector current of 4A is reached the circuit will automatically reduce it to 1A. Injector opening and closing times vary with battery voltage and vary between 0.2 ms at 14 volt and 1.35 ms at 6.5 volt.
- Page 1056 7.8 INJECTION DURATION The base injection duration for different loads and engine speeds is calculated and fine tuned by mapping to ensure that the required A/F ratio is obtained under static operat- ing conditions. (Lambda = 1) Injection durations vary from 1 to 5 milliseconds.
- Page 1057 7.9.2 Engine operating conditions. The following engine operating conditions require additional modifications to the base injection map. 7.9.3 Intake air temperature. The oxygen content of the intake air is proportional to the air density and inversely proportional to the air tempera- ture.
- Page 1058 7.9.5 Cold starting conditions. Definition: Engine speed < 450 r.p.m. During cold start conditions the low inlet manifold tempera- tures cause considerable fuel condensation on the inner walls of the manifold. This condition is known as wall wetting. To ensure correct A/F ratios it is necessary to increase the quantity of fuel injected during cold starting conditions to counteract wall wetting.
- Page 1059 7.9.7 Acceleration conditions. During a sudden increase in throttle opening at constant engine speed the air mass entering the manifold and combus- tion chamber increases almost immediately due to the low density of air, whilst the higher density fuel lags behind. This leads to lean mixtures for a short duration if no compensation is applied.
- Page 1060 7.9.10 Flooded engine conditions. When the engine speed is below 450 r.p.m. and WOT is de- tected the ECU will reduce the base map injection durations by 40% and ignore all cold and post-start corrections in an attempt to prevent further flooding. 7.9.11 Full load operation Under full load operation the engine is required to deliver maximum power and requires a richer A/F ratio.
- Page 1061 IDLE SPEED CONTROL Idle speed is controlled by means of the IACV (Idle Air Control Valve) mounted on the throttle body assembly. The IACV is driven by the IACSM (Idle Air Control Stepper Motor) which is controlled by the ECU. The IACV maintains constant idle speed (temperature depend- ent) under all engine loads.
- Page 1062 IMMOBILISER OPERATION The system contains an immobiliser function which prevents hot-wiring. When the ignition is switched on the ECU will wake up and prompt the ACU for its ID (Identification Code). The ACU will respond by sending its ID to the ECU for com- parison with an ID code stored in the ECU's ROM.
- Page 1063 10 DEFAULT MODE SELECTION When the ECU detects a faulty signal from one of its sensors it will substitute a default signal value to enable the vehicle to be driven with degraded performance (see para- graph 10.1). Faulty sensor Substitute value/sensor _____________________________________________________ ______ Warm engine - 100 øC...
- Page 1064 11 DIAGNOSTICS Various possible methods of fault finding are listed below to reduce down-time of the vehicle. 11.1 Diagnostic codes The CPU continuously monitors its own activities and sensor inputs. If a fault is detected during operation the diagnos- tic lamp is turned on and a default signal value is used to allow the car to be driven with slightly reduced perform- ance.
- Page 1065 DIAGNOSTIC CODES Code Cause _____________________________________________________ Coolant temperature sensor voltage too low Coolant temperature sensor voltage too high TPS voltage too high TPS voltage too low MAT sensor voltage too low MAT sensor voltage too high MAP sensor voltage too high MAP sensor voltage too low Idle control stepper motor failure Timing map selector error...
- Page 1066 11.2 Volt- and ohmmeter No repair work inside the ECU's is possible and recommended. A multimeter could however be used to ensure that the fol- lowing inputs to the ECU are present: 11.2.1 Battery voltage: 11.2.2 The voltage measured between terminals 26B (pos) and 25B (neg) should be equal to the battery voltage (6 and 16 VDC).
- Page 1067 11.2.5 CO potentiometer supply voltage: The voltage between terminal 23B and signal ground should be between 4.7 and 5.2 volt. 11.2.6 MAP sensor supply voltage: The voltage between terminal 24B and signal ground should be between 4.7 and 5.2 volt. 11.2.7 MAP sensor signal voltage: The voltage between terminal 15B and signal ground with ignition on should be:...
- Page 1068 11.2.8 Timing map selector: The resistance between terminal 19B and 22B measured on the harness connector with the ECU removed should be: 97 RON - 470 ohm 93 RON - 220 ohm 87 RON - 4,700 ohm 87D RON - 5,600 ohm 11.2.9 Fuel mixture selector: The resistance between terminal 18B and 11A measured on the harness connector with the ECU removed should be:...
- Page 1069 11.2.10 EWT sensor: The resistance between terminal 16B and on the harness connector with the ECU removed should be: EWT øC Resistance (ohm) 19,700 5,640 2,410 1,177...
- Page 1070 11.2.11 MAT sensor: The resistance between terminal 17B and 11A on the harness with the ECU removed should be: MAT øC Resistance (ohm) 9,977 6,540 5,627 2,290 1,241...