FUEL INJECTION SYSTEM SUBARU SVX 1992 Precaution for Supplemental Restraint System "Airbag" The Supplemental Restraint System "Airbag" helps to reduce the risk or severity of injury to the driver in a frontal collision The Supplemental Restraint System consists of an airbag module (located in the center of the steering wheel), sensors, a control unit, warning light, wiring harness and spiral cable Information necessary to service the safety is included in the "5-5 SUPPLEMENTAL RESTRAINT SYSTEM" of this Service Manual WARNING : To avoid rendering the Airbag system inoperative, which could lead to personal injury or death in the event of a severe frontal collision, all maintenance must be performed by an authorized SVX dealer Improper maintenance, including incorrect removal and installation of the Airbag system, can lead to personal injury caused by unintentional activation of the Airbag system All Airbag system electrical wiring harnesses and connectors are covered with yellow outer insulation Do not use electrical test equipment on any circuit related to the Supplemental Restraint System "Airbag" T+~++ 2-7 M MECHANISM AND FUNCTION ., General , Air Line Fuel Line Induction Control System ., Sensor and Switch Control System Self-diagnosis System C COMPONENT PARTS Intake Manifold and Collector Air Intake Boot and Throttle Body Air Cleaner T TROUBLESHOOTING e Supplemental Restraint System "Airbag" Precautions Pre-inspection Electric Unit Location Troubleshooting Chart for Self-diagnosis System Output Modes of Select Monitor Control Unit I/O Signal Troubleshooting for Engine Starting Failure Troubleshooting Chart with Trouble Code 10 Troubleshooting Chart with Select Monitor 11 General Troubleshooting Table 2-7 [M1ool FUEL INJECTION SYSTEM M MECHANISM AND FUNCTION General permits simple, yet highly precise metering of the fuel Further, all the operating conditions of the engine are converted into electric signals, and this results in additional features of the system, such as large improved adaptability, easier addition of compensating element, etc The MPFI system also has the following features : 1) Reduced emission of harmful exhaust gases 2) Reduced in fuel consumption 3) Increased engine output 4) Superior acceleration and deceleration 5) Superior startability and warm-up performance in cold weather since compensation is made for coolant and intake air temperature The Multi Point Fuel Injection (MPFI) system is a system that supplies the optimum air-fuel mixture to the engine for all the various operating conditions through the use of the latest electronic technology With this system fuel, which is pressurized at a constant pressure, is injected into the intake air passage of the cylinder head The injection quantity of fuel is controlled by an intermittent injection system where the electromagnetic injection valve (fuel injector) opens only for a short period of time, depending on the quantity of air required for one cycle of operation In actual operation, the injection quantity is determined by the duration of an electric pulse applied to the fuel injector and this FUEL INJECTION SYSTEM [M100] 2-7 Radiator main fan Radiator sub fan A/C compressor Inhibitor switch Vehicle speed sensor Speedometer CHECK ENGINE - light Tachometer Resistor Fuel pump modulator Roll over valve Purge control solenoid valve Canister Throttle sensor Auxiliary air control valve By-pass air control solenoid valve Throttle cable Cruise control cable Air flow sensor Fuel filter Fuel pump Induction valve diaphragm Induction control valve PCV valve One way valve Vacuum tank Induction control solenoid valve Puressure regulator Fuel injector Knock sensor (RH) Crank angle sensor Water temperature sensor Knock sensor (LH) Igniter Ignition coil Cam angle sensor Crank angle sensor Spark plug EGR solenoid valve BPT EGR valve Recirculation gas temperature sensor (Col only) Oz sensor (RH) 02 sensor (LH) 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 ZCASE ION ROL SYSTEM O I I G (D FS I C2-049 FUEL INJECTION SYSTEM 2-7 [M201 Air Line ered to the collector chamber and the intake manifold It is then distributed to the respective cylinders to mix with fuel injected by the fuel injectors Thus, the air-fuel mixture is delivered into the cylinder Part of the air branched at the upstream of the throttle body is sent to the by-pass air control solenoid valve which regulates engine idle speed GENERAL Air which is drawn in and filtered by the air cleaner is metered and sent to throttle body via the air intake boot From the throttle body, the air is regulated by the open-close operation of the throttle valve and is delivAir cleaner ~ ~{ Air flow sensor ~~J Throttle body f , ,~~ By-pass air con- trol solenoid valve Collector chamber ~~J Intake manifold Fuel injector J Auxiliary air control valve Cylinder AIR FLOW SENSOR The MPFI system employs a hot-film type air flow sensor This air flow sensor converts the amount of intake air into an electric signal by utilizing the heat transfer phenomenon between the incoming air and heating resistor located in the air intake The features of this air flow sensor type are as follows: 1) High-altitude compensation is automatically made 2) Quick response 3) There are no moving parts 4) It is compact © ~r~ ©~ Air Flow © FLOW a -Hot film Fig Hot wire C2-161 FUEL INJECTION SYSTEM THROTTLE BODY AUXILIARY AIR CONTROL VALVE In response to the depressing stroke of the throttle pedal, the throttle body opens/closes its valve to regulate the air volume to be taken in the combustion chamber During idling, the throttle valve is almost fully closed and the air flow through the throttle body is less than that passing through the carburetor More than half of the air necessary for idling is supplied to the intake manifold via the by-pass air control solenoid valve And the by-pass air control solenoid valve properly controls the number of revolutions in idling, so it does not need to be adjusted Auxiliary air control valve consists of a bimetal, coil heater and rotary valve This valve supplies by-pass air only when engine is cooled Rotary valve AIR OUT AIR IN o Valve fulcrum THROTTLE SENSOR Bimetal This throttle sensor is provided with a potentiometer The throttle sensor converts the opening of the throttle valve into an electric signal, and sends it to the ECU Using this signal, the ECU precisely controls the air-fuel ratio during acceleration and deceleration as well as idling Fig COLLECTOR II L o ®' Coil heater C2-164 The collector is the passage for distributing the intake air into each cylinder It has the induction control valve built in, and the air-induction is controlled by its operation BY-PASS AIR CONTROL SOLENOID VALVE The ECU controls the duty control valve in the by-pass air control solenoid valve to bring the operating engine speed as close to preset idle speed as possible Solenoid Connector Air Inlet Duty control valve Fig IM2o71 2-7 C2-163 2-7 (M3001 FUEL INJECTION SYSTEM Fuel Line level by the pressure regulator on the way to the injectors From the injectors, fuel is injected into the intake manifold where it is mixed with intake air, and is then delivered to the respective cylinders Fuel injection timing and the amount of fuel injected is regulated by the ECU GENERAL Fuel pressurized by the fuel pump built into the fuel tank is delivered to fuel injectors by way of the fuel pipe and fuel filter Fuel is regulated to the optimum pressure F Fuel tank (Fuel)- - Fuel pump Fuel filter I Pressure regulator ECU I I Fuel injector Cylinder Throttle body purge control solenoid valve -D = Pressure regulator #6 Collector J #4 #3 #2 #1 I Fuel filter Fuel cut valve Delivery line Fuel injector Return line Evaporation line Canister Roll over valve Fuel tank Jet pump Fuel pump C2-017 Fig FUEL INJECTION SYSTEM PRESSURE REGULATOR The MPFI system employs a gallery type (side-feed type) fuel injector The gallery type fuel injector is installed in the fuel pipe to allow cooling of the injector by the fuel The features of this type of fuel injector are as follows : 1) High heat resistance 2) Low driving noise 3) Easy to service 4) Small size The fuel injector injects fuel according to the valve open signal received from the ECU The nozzle is attached on the top of the fuel injector The needle valve is lifted by the solenoid coil through the plunger on arrival of the valve open signal Since the injector opening, the lifted level of valve and the regulator-controlled fuel pressure are kept constant, the amount of fuel to be injected can be controlled only by the valve open signal from the ECU Diaphragm I From fuel injector a Valve To fuel tank 2-7 FUEL INJECTOR The pressure regulator is divided into the fuel chamber and the spring chamber by the diaphragm as illustrated below Fuel is fed to the fuel chamber through the fuel inlet connected with the injector A difference in pressure between the fuel chamber and the spring chamber connected with the intake manifold causes the diaphragm to be pushed down, and fuel is fed back to the fuel tank through the return line By returning fuel so as to balance the above pressure difference and the spring force, the fuel pressure is kept at a constant level 250.1 kPa (2 55 kg/cMZ, 36 psi) against the intake manifold pressure To intake manifold [M303] B2-284 Fig Fig 7 2-7 [M4001 FUEL INJECTION SYSTEM Ind uction Control System according to engine operation, thereby increasing the amount of air introduced in the cylinders This increase in the amount of air is generally referred to as the "high" charging efficiency GENERAL The induction control system opens and closes the induction control valve to change the intake air flowrate Pressure vibration in collect or 00 A- - -A : Close o : Op en e a > 90 > U C-7 , yam w 80 70 d U t( O J \ \~ 60 500 10 00 I I Intake valve timin g Pressure in collector + Pressure just i n f ron t o f intake valve + 20 00 30 00 Open ~ - 40 00 5000 Engine sp eed Open ~ 6000 b 7000 ~F 80 00 8500 (rpm) Open ~- ~ -` C2-166 Fig 8 FUEL INJECTION SYSTEM On low engine speed IM4o21 2-7 On high engine speed Induction control valve "CLOSE" Induction control valve "OPEN" C2-167 Fig CONTROL FUNCTION 4,200 [msl The induction control valve operates on the intake manifold pressure transmitted to the diaphragm The intake manifold pressure is controlled by opening/ closing the induction solenoid valve which is determined by the ECU according to the engine speed and fuel injection quantity o m ON i (Close) ~~ OFF (Open) - ~~ Y1 ON OFF OFF (Open) Engine Speed [rpm] Fig 10 C2-168 2-7 [M500] FUEL INJECTION SYSTEM Sensor and Switch 02 SENSOR The OZ sensor is used to sense oxygen concentration in the exhaust gas If the fuel ratio is leaner than the stoichiometric ratio in the mixture (i e excessive amount of air), the exhaust gas contains more oxygen To the contrary, if the fuel ratio is richer than the stoichiometric ratio, the exhaust gas contains hardly any oxygen Therefore, examination of the oxygen concentration in exhaust gas makes it possible to show whether the air/fuel ratio is leaner or richer than the stoichiometric ratio The Oz sensor has a zirconia tube (ceramic) which generates voltage if there is a difference in oxygen concentration between the inside and outside of the tube Platinum is coated on the inside and outside of the zirconia tube for the purpose of catalysis and electrode provision The hexagon screw on the outside is grounded to the exhaust pipe, and the inside is connected to the ECU through the harness A ceramic heater is employed to improve performance at low temperature motive force when the temperature is low The characteristics of the electromotive force stabilize at temperature of approximately 300 to 400°C (572 to 752°F) Electromotive y force Atmosphere V ~ ( U Exhaust gases Exhaust gases Theoretical air-fuel large ratio (Rich signal) To be judged as rich f 0 o Ti x m wO ! Small Small Comparison voltage To be judged as lean (Lean signal) Air-fuel ratio Large B2-287 Fig 12 WATER TEMPERATURE SENSOR The water temperature sensor is located on the water pipe which is made of aluminum alloy Its thermistor changes resistance with respect to temperature A water temperature signal converted into resistance is transmitted to the ECU to control the amount of fuel injection, ignition timing, purge control solenoid valve, etc B2-286 Fig 11 When rich air-fuel mixture is burnt in the cylinder, the oxygen in the exhaust gases reacts almost completely through the catalytic action of the platinum coating on the surface of the zirconia tube This results is a very large difference in the oxygen concentration between the inside and outside, and the electromotive force generated is large When a lean air-fuel mixture is burnt in the cylinder, oxygen remains in the exhaust gases even after the catalytic action, and this results in a small difference in the oxygen concentration The electromotive force is very small The difference in oxygen concentration changes greatly in the vicinity of the optimum air-fuel ratio, and hence the change in the electromotive force is also large By inputting this information into the MPFI control unit, the air-fuel ratio of the supplied mixture can be determined easily The Oz sensor does not generate much electro- 20°C 168°F) 2.5 kn Y 2.5 u c m 80 40 (104) (176) 60 20 (68) (140) -20 (-4) (32) Fig 13 10 Temp °C (°F) B2-288 2-7 [T9UO] FUEL INJECTION SYSTEM U : TROUBLE CODE (52) - PARKING POSITION SIGNAL DIAGNOSIS : Abnormal signal entered from inhibitor switch TROUBLE SYMPTOM : Erroneous idling Poor warm-up performance with select lever in "P" position OK 10 Check contact of ECU connector terminal Not OK OK Replace ECU Repair ECU connector Not OK I Check inhibitor switch Replace inhibitor switch OK Repair or replace harness connector between ECU and inhibitor switch InhIb1tor switch N P o a 860 ECU VB TI B13 C2-373 Fig 98 98 FUEL INJECTION SYSTEM CHECK INPUT SIGNAL FOR ECU 1) Turn ignition switch to "ON" 2) Measure voltage between ECU connector terminal and body when selector lever is on P position or others Connector l;r Terminal/Specified voltage (1359) No - Body/0 V (P Range) (1359) No - Body/8 V, (Other range) CHECK INHIBITOR SWITCH 1) Turn ignition switch to "OFF" 2) Disconnect bulkhead harness connector (1313) 3) Measure resistance between inhibitor switch terminal in connector (T1) Connector £r Terminal/Specified resistance (T1) No - Body/0 12(P Range) (T1) No - Body/1 MSS (Other range) T1 ~ _ _ x ~,~ ~ a a z 12 11 10 a y 313'~ Fig 99 C2-362 Refer to C.3-2 99 [T9U2) 2-7 2-7 [T9VOI FUEL INJECTION SYSTEM V: TROUBLE CODE (55) - RECIRCULATION GAS TEMPERATURE SENSOR 1 Check input signal for ECU Check contact of ECU connector terminal OK Replace ECU Repair ECU connector Not OK F Not OK I Check harness connector between ECU and recirculation gas temperature sensor Replace or replace harness connector OK Replace recirculation gas temperature sensor a : 859 d : Bbl B7 e4 e11 E2 Recirculation gas temperatule sensor E13 ECU Fed/Cal Cal only C2-375 Fig 100 100 FUEL INJECTION SYSTEM CHECK INPUT SIGNAL FOR ECU 1) Turn ignition switch to "ON" 2) Measure voltage between ECU connector terminal and body Connector & Terminal/Specified voltage (B59) No - Body/ - 4.8 V [20°C (68°F)] 0.4 - V [100°C (212°F)] CHECK HARNESS CONNECTOR BETWEEN ECU AND RECIRCULATION GAS TEMPERATURE SENSOR 1) Turn ignition switch to "OFF" 2) Disconnect recirculation gas temperature sensor connector 3) Measure resistance of harness connector between gas temperature sensor and ECU Connector £r Terminal/Specified resistance (E59) No - (E13) No 2/0 f1 (E59) No 11 - (E13) No 1/0 f1 E13 S B59 1 1 l l 1 a g im 1213141516171819202122 C2-376 Fig 101 4) Measure resistance between sensor connector terminal and body to check short circuit Connector Ft Terminal/Specified resistance (E13) No - Body/1 Mid 101 [T9V2] 2-7 2-7 [T9W0] FUEL INJECTION SYSTEM W: TROUBLE CODE (56) - EGR SYSTEM DIAGNOSIS : Mechanical trouble for EGR valve, EGR vacuum controller and/or EGR line TROUBLE SYMPTOM : Poor driving performance on low engine speed EGR valve may be stuck "OPEN" or "CLOSE" Refer to C.2-1 "EGR system" 102 FUEL INJECTION SYSTEM [T10A0] 2-7 10 Troubleshooting Chart with Select Monitor A : BASIC TROUBLESHOOTING CHART If no trouble codes appear in the Read Memory, U-Check or D-check mode (although problems have occurred or are occurring), measure performance characteristics of sensors, actuators, etc , in the "F' mode (select-monitor function), and compare with the "basic data" to determine the cause of problems Applicable cartridge of select monitor : No 498347500 Problem occurs No trouble codes appear in Read Memory, U-Check or D-check mode Measure each item in "I"' mode (select-monitor function) Refer to "General Troubleshooting Table" [T900] for inspection order I Compare measured value with "specified data " Determine I item which is outside "specified data" 11 * Check sensor or actuator corresponding with item outside "specified data " * When item is not constantly outside "specified data," problem may be due to poor harness contact Disconnect or connect affected sensor/actuator connector or shake its harness to check if trouble code appears 103 2-7 [T10B0] FUEL INJECTION SYSTEM B : MODE F00 - ROM ID number (YEAR) CONDITION : Ignition switch "ON" SPECIFIED DATA : Presentation display; 1992 (F00) EGI Probable cause (Item outside "specified data") Error Check for loose or disconnected connector, and discontinued circuit, etc Error Check for poor contact of cartridge, or different type cartridge C: MODE 01 - Battery voltage (VB) CONDITION : (1) Ignition switch "ON" (2) Idling after warm-up SPECIFIED DATA : (1) 10 to 12V (2) 12 to 14V Probable cause (Item outside "specified data") Check battery voltage and electrolyte's specific gravity 1 Battery Check regulating voltage (On no-load) Check alternator ICharging system D: MODE F02, F03 - Vehicle speed signal (VSP) CONDITION : Driving at constant speed SPECIFIED DATA : Compare speedometer with monitor indications Probable cause (Ite m outside "specified data") Harness connector damaged Poor contact of connector terminal l Harness connector between ECU and vehicle speed sensor NO Vehicle speed sensor ` I a F02 : Vehicle speed is indicated in mile per hour b F03 : Vehicle speed is indicated in kilometer per hour 104 Check vehicle speed sensor (Refer to [T7M0]) [T10Go] 2-7 FUEL INJECTION SYSTEM E : MODE F04 - Engine speed signal (EREV) CONDITION : Operate engine at constant speed SPECIFIED DATA : Compare engine speed indicated on tachometer Probable cause (Item outside "specified data") Crank angle sensor P' CONDITION : Idling after warm-up Check output signal from crank angle sensor (Refer to [T7B0]) SPECIFIED DATA : F05 : 176 to 194 degF F06 : 80 to 90 degC Probable cause (Item outside "specified data") ` Water temperature sensor Check water temperature sensor (Refer to [T7F0]) a F05: Water temperature is indicated in "degF" b F06: Water temperature is indicated in "degC" CONDITION : " Idling after warm-up " Shift in "N" position SPECIFIED DATA : 12 deg to 28 deg Probable cause (Item outside "specified data") Load data Check "MODE F09" OK Air flow sensor Check "MODE F08" (Air flow signal) OK Throttle sensor ~ Check "MODE F10" (Throttle position signal) OK Knock sensor check "MODE F21" (Knock sensor signal) 105 2-7 [T10HOI FUEL INJECTION SYSTEM H : MODE F08 - Air flow signal (QA) CONDITION : Idling after warm-up SPECIFIED DATA : 0.8 to V Probable cause (Item outside "specified data") Check air flow sensor output signal (Refer to [T7G0]) Air flow sensor CONDITION : Idling after warm-up SPECIFIED DATA : 15 to 25 e Probable cause (Item outside "specified data") Air flow sensor Check "MODE : F08" I Engine speed Check "MODE : F04" Check crank angle sensor (Refer to [T7A0]) r Crank angle sensor J: MODE F10 - Throttle position signal (THV) CONDITION : Check while changing throttle valve from "full-close" to "full-open" SPECIFIED DATA : 0.5 -+ V (Voltage change must be smooth ) Probable cause (Item outside "specified data") Check throttle sensor (Refer to [T7K0]) Throttle sensor 106 FUEL INJECTION SYSTEM [T1OL01 2-7 K: MODE F11 - Injector pulse width (TIM) CONDITION : Idling after warm-up SPECIFIED DATA : to mS Engine under load (Load data) Check "MODE : F09" OK A/F correction coefficient Check "MODE : F19" and "MODE : F20" OK Water temperature signal Check "MODE : F05" or "MODE : F06" y 02 sensor signal _- OK Check "MODE : F13" and "MODE : F14" " OK Check "MODE : F02" or "MODE : F03" Vehicle speed signal OK Air flow signal Check "MODE : F08" OK By-pass air control Check "MODE : F12" OK Check "MODE : F01" Battery voltage L: MODE F12 - By-pass air control (ISC) SPECIFIED DATA : CONDITION : Idling after warm-up A/C "OFF" Radiator fan "OFF" Battery voltage: Greater than 13 V 30 to 40% Sea level (Not high altitudes) Probable cause (Item outside "specified data") I Check "MODE : F05" or "MODE : F06" Water temperature signal OK I Neutral switch Check neutral switch (Refer to [T7T0]) I OK Check parking switch (Refer to [T7U0]) Parking switch 107 I 2-7 [T10M0I FUEL INJECTION SYSTEM M : MODE F13, F14 - 02 sensor signal 1, (01R, 02L) CONDITION : Idling after warm-up L SPECIFIED DATA : 0to1 0V Probable cause (Item outside "specified data") I Injector pulse width Check "MODE : F11" -7 OK Check Oz sensor or (Refer to [T710] or [T7L0]) OZ sensor or N : MODE F15, F17 - 02 Max (02 Rmax, 02 Lmax) CONDITION : Idling after warm-up SPECIFIED DATA : to 0.9 V Probable cause (Item outside "specified data") I Injector pulse width I Check "MODE : F11" I OK Check OZ sensor or (Refer to [T710] or [77L0]) 2.102 sensor or O: MODE F16, F18 - 02 Min (02 Rmin, 02 Lmin) CONDITION : Idling after warm-up SPECIFIED DATA : 05 to 12 V Probable cause (Item outside "specified data") Injector pulse width Check "MODE : F11" OK ` OZ sensor or 108 Check OZ sensor or (Refer to [T710] or [T7L0]) FUEL INJECTION SYSTEM [T1oso] 2-7 P: MODE F19, F20 - A/F correction coefficient 1, (ALPHA1, ALPHA 2) CONDITION : Idling after warm-up SPECIFIED DATA : - to + Probable cause (Item outside "specified data") I OZ sensor signal I- I Check "MODE : F13" and "MODE : F14" OK Air flow signal Check "MODE : F08" OK Injector pulse width Check "MODE : F11° Q : MODE F21 - Knock sensor signal (RTRD) CONDITION: Engine warm-up Engine speed low to high SPECIFIED DATA : - 10 to + 10 deg Probable cause (Item outside "specified data Check knock sensor and/or (Refer to [T7F0], [T710]) Knock sensor and/or CONDITION : Idling after warm-up SPECIFIED DATA : Probable cause (Item outside "specified data") ` Purge control solenoid valve Check purge control solenoid valve (Refer to [T700]) S: MODE F23 - Atmospheric pressure (BARO P) CONDITION : Ground surface (Not high altitude) Engine at idle SPECIFIED DATA : 760 mmHg* * : "-9 to + 10 mmHg" changes at an altitude of 100 meters Probable cause (Item outside "specified data") Atmospheric pressure sensor Replace ECU 109 2-7 FUEL INJECTION SYSTEM [T10T0] T: MODE FAO - ON H OFF SIGNAL LED No Description Signal name Ignition switch A/C switch Idle switch A/C pressure switch Presentation IG AC ID AP - - - Requirement for LED "ON" Ignition switch is turned to "ON" A/C relay is in operation Throttle valve is fully closed A/C system is in economy mode Selector lever is in " N" position Power steering switch is turned to "ON" - Neutral position switch NT 10 Power steering switch - PS - - - IG AC ID AP NT PS C2-377 Fig 102 U : MODE FA1 - ON H OFF SIGNAL Description Signal name - LED No Test mode position Read memory mode position - LID RM - 10 Engine torque control Parking position switch Fed /Cal discrimination - TR PK FC - LID RM TR PK FC Requirement for LED "ON" DIAG terminal is connected into the test mode terminal in diagnosis connector DIAG terminal is connected into the read memory terminal in diagnosis connector The torque that the engine transmits to the transmission is controlled Selector lever is in "P" position 49-states and Canada model Presentation - C2-378 Fig 103 110 FUEL INJECTION SYSTEM V: MODE FA2 - ON H OFF SIGNAL LED No 10 Description Signal name Radiator sub fan Radiator main fan Fuel pump modulator EGR solenoid valve Induction solenoid valve - Presentation R2 R1 FP ER IH - R2 R1 FP ER IH - - Requirement for LED "ON" Radiator sub fan is in operation Radiator main fan is in operation Fuel pump is in normal operation EGR solenoid valve is in operation Induction solenoid valve is in operation C2-379 Fig 104 W: MODE FA3 - ON H OFF SIGNAL Description Signal name LED No - - - - - - - - - - - - Knock sensor and/or KS - 10 - - KS Requirement for LED "ON" Engine is knocking Presentation - C2-380 Fig 105 111 [Tlowol 2-7 FUEL INJECTION S YSTEM 2-7 [T10X0I X: MODE FA4 - ON H OFF SIGNAL Description Signal name LED No - - - - 10 FP - - - I - - - - Fuel pump relay is in operation - Fuel pump Requirement for LED "ON" Presentation - C2-381 Y: MODE FA5 - ON H OFF SIGNAL Description Signal name LED No - - - - - Oz monitor RH 10 - OR - - - - Oz monitor LH - - Requirement for LED "ON" A/F ratio of right side cylinder is rich A/F ratio of left side cylinder is rich Presentation - OL OR C2-415 112 ... injectors by way of the fuel pipe and fuel filter Fuel is regulated to the optimum pressure F Fuel tank (Fuel) - - Fuel pump Fuel filter I Pressure regulator ECU I I Fuel injector Cylinder Throttle... cylinder In other words, fuel injection is completed just before the intake valve begins to open 14 FUEL INJECTION SYSTEM [M603] 2-7 1) Fuel injection characteristics Fuel injection timing is basically... High oxygen Fuel injection increases density Fuel injection decreases T 1 Lean signal Rich signal O, sensor Lean air -fuel ratio Detection Rich air -fuel ratio B2-304 Fig 28 16 FUEL INJECTION SYSTEM