;;^d;‘;r; 1987 FUEL INJECTION SYSTEM119 1 - Land Rover

1 ;;^d; ;r; 1987 fuel INJECTION SYSTEM 119 I IRR1752 EFUEL INJECTION - Circuit Diagram1. 40 way connector to Electronic Control Unit(ECU).2. Lambda sensor (left side - bank A).3. Lambda sensor (right side - bank 8).4. By-pass air valve (stepper motor) (fast idle).5. Lambda sensor screened Fuse 18 - main fuse Inertia fuel Ignition Speed transducer (road speed input).7 1. Neutralswitch (automatic gearbox) (loadinput).12. Pick-up point-air conditioning circuit (loadinput).

2 13. Diagnostic In-line Coil/-ve (engine RPM input).17. Coolanttemperaturethermistor (sensor)(input).18. fuel temperature thermistor (sensor) (input).19. Throttle Air flow fuel pump Main Injectors-l to Pick-up point warninasymbol (instrumentbinnacle).= = =Denotes screened : Reference to left and right side is made when viewing vehicle from colour codeBBlackGGreenRRedUBlue0 OrangeM WhiteNBrownPPurpleYYellowThe last letter of a colour code denotes the : JULY 88 SCreyKPinkLGLight green1.

3 :;l-l19 fuel INJECTION SYSTEM1987 rot;; , , ., ,. :ECU AND RELAY8 FWL RCOULATOR41 RCA1 OF ENOINEFUEL WYP111 fuel TANAUNDER RIGHT FRONTOEATF:lJEL FILTER ON CHAlllll#1La lNJcc10nsFOR ENONEROAO OFEED WUtTIIANOOUCERION CNAIOWCOOLANT tEYPERATU(IEl LNIOR FRONT OF ENOMFUEL TEYFEIIATUREl EN10 RliNOiNE FULL RAILA1111 IV cA1I VALVEREAR OF ENOWE BAVIA-RIHOT WIG ARFLOW8 ENaoR FRONT LEFTl EIE OF LNONE l AV\ . /,..!TWROTTLE FOTENTIOYETEFRONT OFTHROTTLE VALVElONRlON COLLEFTIDE OF ENWIE l AVRR2178E2 REVISED: JULY 88ggf.)

4 I 1987 fuel INJECTION SYSTEM 119 1 INTRODUCTIONThe Electronic fuel INJECTION system provides areliable and efficient microprocessor controlled fuelmanagement function of the system is to supply the exactamount of fuel directly into the inlet manifoldaccording to the prevailing engine monitor these conditions, various sensors arefitted to the engine to measure engine from the sensors is received by the ElectronicControl Unit ( ), the will thendetermine the exact amount of fuel required at having received data from the sensorsproduces pulses, the length of which will determinethe simultaneous open time of each bank ofinjectors in turn, which will govern the amount offuel CONTROL UNIT-ECUThe Electronic fuel INJECTION system is controlled bythe which is located under the front righthand seat.

5 The control unit is a microprocessor withintegrated circuits and components mounted onprinted circuit boards. The is connected tothe main harness by a 40 pin eight fuel injectors are fitted between thepressurized fuel rail and inlet manifold. Each injectorcomprises a solenoid operated needle valve with amovable plunger rigidly attached to the nozzlevalve. When the solenoid is energized the plungeris attracted off its seat and allows pressurized fuelinto the intake COOLANT TEMPERATURE THERMISTOR(SENSOR)The coolant thermistor (sensor) is located by thefront left hand branch of the intake manifold.

6 Thethermistor provides engine coolant information tothe The on receiving the signal fromthe thermistor will lengthen slightly the time thatthe injectors are open, and reducing this time asthe engine reaches normal operating TEMPERATURE THERMISTOR (SENSOR)The fuel temperature thermistor (sensor) is locatedin the fuel rail forward of the ram housing. Thethermistor sends fuel temperature data to , the on receiving the data will adjustthe injector open time accordingly to producegood hot starting in high ambient AIR VALVE (STEPPER MOTOR)The bypass valve is screwed into a housing attachedto the rear of the plenum chamber, between theplenum chamber and bulkhead.

7 The bypass valvehas two windings which enable the motor to beenergised in both directions thus opening orclosing the air valve as required by the bypass valve will open and allow extra air intothe plenum chamber to maintain engine idle speedwhen the engine is under increased (Electrical andMechanical) bypass valve will control engine idle speedwhen the vehicle is SENSORS (0, SENSORS)The two Lambda sensors are located fonvard of thecatalysts mounted in the exhaust sensors monitor the oxygen content of theexhaust gases and provide feedback information ofthe air/ fuel ratio to the Each sensor is heatedby an electrical element to improve its responsetime when the ignition is switched : APR.

8 873 fuel INJECTION SYSTEM1987 rGv;; fuel PRESSURE REGULATORTHROlTLE POTENTIOMETERThe fuel pressure regulator is mounted in the fuelrail at the rear of the plenum chamber. Theregulator is a mechanical device controlled byplenum chamber vacuum, it ensures that fuel railpressure is maintained at a constant pressuredifference of bar above that of the pressure exceeds the regulator setting excessfuel is returned to the fuel PUMPThe electric fuel pump is located in the fuel tank,and is a self priming wet pump.

9 The motor isimmersed in the fuel within the FLOW SENSORThe hot-wire air flow sensor is mounted on abracket attached to the left hand valance, rigidlyconnected to the air cleaner and by hose to theplenum chamber inlet air flow sensor consists of a cast alloy bodythrough which air flows. A proportion of this airflows through a bypass in which two wire elementsare situated: one is a sensing wire and the other isa compensating wire.

10 Under the control of anelectronic module which is mounted on the air flowsensor body, a small current is passed through thesensing wire to produce a heating effect. Thecompensating wire is also connected to the modulebut is not heated, but reacts to the temperature ofthe air taken in, as engine intake air passes over thewires a cooling effect takes throttle potentiometer is mounted on the sideof the plenum chamber inlet neck and is directlycoupled to the throttle valve potentiometer is a resistive device suppliedwith a voltage from the Movement of thethrottle pedal causes the throttle valve to open.