1991 LEXUS SC400 engine

INSTALLATION OF FUEL PUMP
(See Components on page FI±19)
1. INSTALL FUEL PUMP (a) Install a new gasket to the pump set plate.
(b) Connect the fuel hose to the fuel pump bracket, andinstall the fuel pump and bracket assembly with the
three nuts.
Torque: 5.4 N Vm (55 kgf Vcm, 48 in. Vlbf)
(b) Install the fuel pump set plate with the eight bolts.
Torque: 3.9 N Vm (40 kgf Vcm, 35 in. Vlbf)
2. INSTALL PARTITION COVER
Install the partition cover with butyl tape.
3. INSTALL SEAT BACK AND CUSHION
4. CONNECT FUEL PUMP CONNECTOR
5. INSTALL LUGGAGE COMPARTMENT TRIM COVER
6. INSTALL SPARE TIRE
7. INSTALL LUGGAGE COMPARTMENT FLOOR MAT
8. CONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
9. START ENGINE, AND CHECK FOR FUEL LEAKS
±
EFI SYSTEM Fuel System (Fuel Pump)FI±23
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FUEL SYSTEM
Fuel Pump
ON±VEHICLE INSPECTION
1. CHECK FUEL PUMP OPERATION(a) Using SST, connect terminals +B and FP of the check
(ºDIAGNOSISº) connector.
SST 09843±18020
(b) Turn the ignition switch ON.
NOTICE: Do not start the engine.
(c) Check that there is pressure in the fuel inlet hose from the fuel filter.
HINT: At this time, you will hear fuel return noise.
(d) Turn the ignition switch OFF.
(e) Remove SST from the check connector.
SST 09843±18020 FI±17
± Fuel System (Fuel Pump)EFI SYSTEM
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If there is no pressure, check the following parts:w Fuses
w EFI main relay
w Fuel pump ECU
w Fuel pump
w Engine & ECT ECU
w Wiring connections
2. CHECK FUEL PRESSURE (a) Check the battery voltage above 12 volts.
(b) Disconnect the cable from the negative (±) terminal ofthe 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.
(c) (Exc. USA Spec.) Remove the filter from the VSV (for EGR system).
(d) Remove the union bolt holding the LH deliver pipe to the
rear fuel pipe. Remove the two gaskets.
HINT:
w Put a suitable container or shop towel under the cold
start injector pipe.
w Slowly loosen the union bolt.
(e) Install the rear fuel pipe and SST (pressure gauge) to the LH delivery pipe with three new gaskets and the
union bolt.
SST 09268±45012
Torque: 39 N Vm (400 kgf Vcm, 29 ft Vlbf)
(f) Wipe off any splattered gasoline.
(g) (Exc. USA Spec.)
Reinstall the filter to the VSV.
(h) Using SST, connect terminals B and FP of the check (ºDIAGNOSISº) connector.
SST 09843±18020
(i) Reconnect the cable to the negative (±) terminal of the
battery.
FI±18
EFI SYSTEM
± Fuel System (Fuel Pump)
WhereEverybodyKnowsYourName

(j) Turn the ignition switch ON.
(k) Measure the fuel pressure.
Fuel pressure: 265±304 kPa(2.7±3.1 kgf/cm
2, 38±44 psi)
If pressure is high, replace the fuel pressure regulator.
If pressure is low, check the following parts:w Fuel hoses and connections
w Fuel pump
w Fuel filter
w Fuel pressure regulator
(l) Remove SST from the check connector.
SST 09843±18020
(m) Start the engine.
(n) Disconnect the vacuum sensing hose from the fuel pressure regulator, and plug the hose end.
(o) Measure the fuel pressure at idling.
Fuel pressure: 265±304 kPa
(2.7±3.1 kgf/cm
2, 38±44 psi)
(p) Re connect the vacuum sensing hose to the fuel
pressure regulator.
(q) Measure the fuel pressure at idling.
Fuel pressure: 196±235 kPa
(2.0±2.4 kgf/cm
2, 28±34 psi)
If pressure is not as specified, check the vacuum sensing
hose and fuel pressure regulator.
(r) Stop the engine. Check that the fuel pressure remains147 kPa (1.5 kgf/cm
2, 21 psi) or more for 5 minutes after
the engine is turned off.
If pressure is not as specified, check the fuel pump, pressure
regulator and/or injectors.
(s) After checking fuel pressure, disconnect the battery negative (±) cable and carefully remove the SST to
prevent gasoline from splashing.
SST 09268±45012
(t) Connect the rear fuel pipe to the delivery pipe with two new gaskets and the union bolt.
Torque: 39 N Vm (400 kgf Vcm, 29 ft Vlbf)
(u) (Exc. USA spec.)
Reinstall the filter to the VSV.
(v) Reconnect the cable to the negative (±) terminal of the
battery.
(w) Check for fuel leaks. (See page FI±16) FI±19
EFI SYSTEM
± Fuel System (Fuel Pump)
WhereEverybodyKnowsYourName

INSTALLATION OF FUEL PUMP
(See Components on page FI±20)
1. INSTALL FUEL PUMP (a) Install a new gasket to the pump set plate.
(b) Connect the fuel hose to the fuel pump bracket, andinstall the fuel pump and bracket assembly with the
three nuts.
Torque: 5.4 N Vm (55 kgf Vcm, 48 in. Vlbf)
(b) Install the fuel pump set plate with the eight bolts.
Torque: 3.9 N Vm (40 kgf Vcm, 35 in. Vlbf)
2. INSTALL PARTITION COVER
Install the partition cover with butyl tape.
3. INSTALL SEAT BACK AND CUSHION
4. CONNECT FUEL PUMP CONNECTOR
5. INSTALL LUGGAGE COMPARTMENT TRIM COVER
6. INSTALL SPARE TIRE
7. INSTALL LUGGAGE COMPARTMENT FLOOR MAT
8. CONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
9. START ENGINE, AND CHECK FOR FUEL LEAKS
FI±24
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

6. REMOVE UPPER HIGH±TENSION CORD COVER(a) Remove the two mounting bolts.
(b) Disconnect the front side claw groove of the cord coverfrom the claw of the lower cover, and remove the cord
cover.
7. REMOVE RH ENGINE WIRE COVER Remove the bolt and wire cover.
8. REMOVE LH ENGINE WIRE COVER Remove the two bolts and wire cover.
9. REMOVE VSV FOR EVAP SYSTEM Remove the two bolts, and disconnect the VSV from cylinder
head and timing belt cover.
10. REMOVE RH NO.3 TIMING BELT COVER Remove the three bolts and timing belt cover.
FI±28
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