ignition switch LEXUS SC400 1991 Service Repair Manual

REMOVAL OF FUEL PUMP
(See Components on page FI±20)
CAUTION: Do not smoke or work near an open flame
when working on the fuel pump.
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and negative (±) terminal
cable is disconnected from the battery.
2. REMOVE LUGGAGE COMPARTMENT FLOOR MAT
3. REMOVE SPARE TIRE
4. REMOVE LUGGAGE COMPARTMENT TRIM COVER
5. DISCONNECT FUEL PUMP CONNECTOR
6. REMOVE SEAT CUSHION AND BACK
7. REMOVE PARTITION COVER Using a scraper, pry out the partition cover.
8. REMOVE FUEL PUMP (a) Remove the eight bolts, and disconnect the fuel pumpset plate from the fuel tank.
(b) Remove the three nuts, and disconnect the fuel pump bracket from the fuel tank.
(c) Disconnect the fuel hose from the fuel pump bracket, and remove the fuel pump, bracket and set plate
assembly. FI±21
EFI SYSTEM
± Fuel System (Fuel Pump)
WhereEverybodyKnowsYourName

REMOVAL OF COLD START INJECTOR
(See Components on page FI±26)
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OF BATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. DRAIN ENGINE COOLANT (See page CO±6)
3. REMOVE THROTTLE BODY COVER (a) Remove the mounting cap nut.
(b) Loosen the two bolts, and remove the throttle bodycover.
4. DISCONNECT CONTROL CABLES FROM THROTTLE BODY
Disconnect the following cables:(1) Accelerator cable
(2) A/T throttle control cable
(3) (w/ Cruise Control System)
Cruise control actuator cable
5. REMOVE INTAKE AIR CONNECTOR (a) Disconnect the following hoses:(1) Air hose from ISC valve
(2) Air hose (from PS air control valve) from intake air connector
(b) Remove the bolt holding the intake air connector to the cylinder head cover.
(c) Loosen the two hose clamps.
(d) Disconnect the intake air connector from the throttle body and air cleaner hose, and remove the intake air
connector. FI±27
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName

(e) Using SST, connect terminals +B and FP of the check(ºDIAGNOSISº) connector.
SST 09843±18020
(f) Reconnect the cable to the negative (±) terminal of the
battery.
(g) Turn the ignition switch ON.
NOTICE: Do not start the engine.
(h) Connect the test probes of the SST (wire) to the battery, and check that the fuel spray is as shown.
SST 09842±30055
NOTICE: Perform this check within the shortest possible
time.
3. INSPECT LEAKAGE (a) In the condition above, disconnect the test probes ofSST (wire) from the battery and check fuel leakage from
the injector.
SST 09842±30055
Fuel drop: One drop or less per minute
(b) Disconnect the cable from the negative (±) terminal of the battery.
(c) Remove SST.
SST 09268±41045, 09842±30050 and 09843±18020
FI±34
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName

REMOVAL OF INJECTORS
(See Components on page FI±27 )
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OF
BATTERY
CAUTION: Turn the ignition switch to ºLOCKº.
Disconnect the cable from the negative (±) terminal of the
battery. Wait at least 20 seconds before proceeding with
work.
2. DRAIN ENGINE COOLANT
3. REMOVE THROTTLE BODY WITH INTAKE AIR CONNECTOR
(See steps 2 to 6 on pages EM±10 and 11)
4. DISCONNECT NO.1 FUEL PIPE FROM DELIVERY PIPE Remove the union bolt and two gaskets, and disconnect the
fuel pipe.
HINT:
wPut a suitable container or shop towel under the delivery
pipe.
w Slowly loosen the union bolt.
5. DISCONNECT NO. 2 FUEL PIPE FROM FUEL PRESSURE
REGULATOR
Remove the union bolt and two gaskets, and disconnect the
fuel pipe from the pressure regulator.
HINT:
w Put a suitable container or shop towel under the
pressure regulator.
w Slowly loosen the union bolt.
6. REMOVE AIR INTAKE CHAMBER STAYS Remove the bolt, nut and intake chamber stay.
Remove the No. 1 and No. 2 stays.
FI±28
±
EFI SYSTEM Fuel System (Injectors)
WhereEverybodyKnowsYourName

(g) Install the grommet and a new O±ring to the injector.
(h) Connect SST (hose) to the injector with SST (union),and hold the injector and union with SST (clamp).
SST 09268±41045
(i) Put the injector into the graduated cylinder.
HINT: Install a suitable vinyl hose onto the injector to prevent
gasoline from splashing out.
(j) Using SST, connect terminals +B and FP of the check (ºDIAGNOSISº) connector.
SST 09843±18020
(k) Reconnect the cable to negative (±) terminal of battery.
(l) Turn the ignition switch ON.
NOTICE: Do not start the engine.
(m) Connect SST (wire) to the injector and battery for 15 seconds, and measure the injection volume with a
graduated cylinder. Test each injector two or three
times.
SST 09842±30070
Volume: 70±88 cm3 (4.3±5.4 cu in.) per 15 sec.
Difference between each injector:
9 cm
3 (0.5 cu in.) or less
If the injection volume is not as specified, replace the injector.
2. INSPECT LEAKAGE (a) In the condition above, disconnect the test probes ofSST (wire) from the battery and check the fuel leakage
from the injector.
SST 09842±30070
Fuel drop: One drop or less per minute
(b) Disconnect the battery negative (±) cable.
(c) Remove SST.
SST 09268±41045 and 09843±18020
(d) Reconnect the fuel inlet hose to the fuel tube.
SST 09631±22020
Torque: 30 N Vm (310 kgf Vcm, 22 ft Vlbf)
HINT: Use a torque wrench with a fulcrum length of 30 cm
(11.81 in.).
±
EFI SYSTEM Fuel System (Injectors)FI±31
WhereEverybodyKnowsYourName

COMPONENTS
REMOVAL OF AIR FLOW METER
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Turn the ignition switch to ºLOCKº. Discon-
nect the cable from the negative (±) terminal of the bat-
tery. Wait at least 20 seconds before proceeding with
work.
2. REMOVE AIR CLEANER HOSE (a) Disconnect the following hoses:(1) PS air hose from No. 4 timing belt cover
(2) PCV hose from No. 2 cylinder head cover
(b) Loosen the two hose clamps and remove the air cleaner
hose.
FI±40
±
EFI SYSTEM Air Induction System (Air Flow Meter)
WhereEverybodyKnowsYourName

COMPONENTS FOR REMOVAL AND
INSTALLATION
REMOVAL OF FUEL PRESSURE
REGULATOR
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE INTAKE AIR CONNECTOR (a) Disconnect the following hoses:(1) Air hose from ISC valve
(2) Air hose (from PS air control valve) from intake air
connector FI±43
EFI SYSTEM
± Fuel System (Fuel Pressure Regulator)
WhereEverybodyKnowsYourName

ENGINE SPEED SENSOR
COMPONENTS FOR REMOVAL AND
INSTALLATION
REMOVAL OF ENGINE SPEED SENSOR
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE ENGINE UNDER COVER
3. DISCONNECT ENGINE SPEED SENSOR CONNECTOR
4. REMOVE ENGINE SPEED SENSOR Remove the bolt and engine speed sensor.
INSTALLATION OF ENGINE SPEED
SENSOR
1. INSTALL ENGINE SPEED SENSOR
Torque: 6.4 N Vm (65 kgf Vcm, 56 in. Vlbf)
2. CONNECT ENGINE SPEED SENSOR CONNECTOR
3. INSTALL ENGINE UNDER COVER
4. CONNECT CABLE TO NEGATIVE TERMINAL OF
BATTERY
IG±30
±
IGNITION SYSTEM Engine Speed sensor
WhereEverybodyKnowsYourName

IGNITION MAIN RELAY
INSPECTION OF IGNITION MAIN RELAY
1. DISCONNECT CABLE FROM NEGATIVE TERMINAL OFBATTERY
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE IGNITION MAIN RELAY LOCATION: In the engine compartment relay box.
3. INSPECT IGNITION MAIN RELAY
A. Inspect relay continuity
(a) Using an ohmmeter, check that there is continuitybetween terminals 3 and 6.
(b) Check that there is continuity between terminals 4 and 5.
(c) Check that there is no continuity between terminals 1 and 2.
If continuity is not as specified, replace the relay.
B. Inspect relay operation (a) Apply battery voltage across terminals 3 and 6.
(b) Using an ohmmeter, check that there is continuitybetween terminals 1 and 2.
(c) Apply battery voltage across terminals 4 and 5.
(d) Using an ohmmeter, check that there is continuity between terminals 1 and 2.
If operation is not as specified, replace the relay.
4. REINSTALL IGNITION MAIN RELAY
5. RECONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
±
IGNITION SYSTEM Ignition Main RelayIG±31
WhereEverybodyKnowsYourName

PRECAUTIONS
1. Do not leave the ignition switch on for more than 10minutes if the engine will not start.
2. With a tachometer connected to the system, connect the tester probe of the tachometer to terminal IG
of the
check (ºDIAGNOSISº) connector.
HINT:
wAllow the engine to warm up to normal operation
temperature.
w Set the tachometer to the 4±cylinder range.
3. As some tachometers are not compatible with this ignition system, we recommend that you confirm the
compatibility of your unit before use.
4. Never allow the tachometer terminal to touch ground as this could damage the igniter and/or ignition coil.
5. Do not disconnect the battery when the engine is running.
6. Check that the igniter is properly grounded to the body.
±
IGNITION SYSTEM PrecautionsIG±3
WhereEverybodyKnowsYourName