1991 LEXUS SC400 fuel pressure

INSPECTION OF INJECTORS
1. INSPECT INJECTOR INJECTIONCAUTION: Keep injector clear of sparks during the test.
(a) Disconnect the fuel inlet hose from the fuel tube.
(b) Connect SST (hose) to the fuel inlet tube with SST(union). Tighten the flare nut on the fuel tube.
SST 09268±41045 (90405±52010)
Torque: 30 N Vm (310 kgf Vcm, 22 ft Vlbf)
HINT: Use SST. (See page FI±15)
SST 09631±22020
(c) Loosen the lock nut, and remove the pressure regulator from the RH delivery pipe. Remove the O±ring from the
pressure regulator.
(d) Install a new O±ring to the fuel inlet of the pressure regulator.
(e) Connect SST (hose) to the pressure regulator with SST (union). Tighten the lock nut on the pressure regulator.
SST 09268±41045 (09268±52010)
Torque: 29 N Vm (300 kgf Vcm, 22 ft Vlbf)
(f) Connect the fuel return hose to the fuel outlet of the
pressure regulator with SST (union), two new gaskets
and union bolt.
SST 09268±41045 (09268±41070)
FI±52EFI SYSTEM ± Fuel System (Injectors)
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(e) Reinstall the fuel pressure regulator to the RH deliverypipe.
w Fully loosen the lock nut on the pressure regulator.
w Apply a light coat of gasoline to a new O±ring, and
install it to the pressure regulator.
w Completely insert the pressure regulator into the
delivery pipe by hand.
w Turn the pressure regulator counterclockwise until
the vacuum sensing port faces in the direction
indicated in the illustration.
INSTALLATION OF INJECTORS
(See Components on page FI±49)
1. INSTALL INJECTORS AND DELIVERY PIPE (a) Install the grommet to each injector.
(b) Apply a light coat of gasoline to a new O±ring and install
it to each injector.
(c) W h i l e t u r n i n g t h e i n j e c t o r c l o c k w i s e a n d counterclockwise, push it to the delivery pipes. Install
the eight injectors.
(d) Position the injector connector outward.
(e) Place the eight insulators and four spacers in position on the intake manifold.
FI±54
EFI SYSTEM
± Fuel System (Injectors)
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(f) Place the eight injectors and two delivery pipesassembly in position on the intake manifold.
(g) Temporarily install the c onnector bracket and four
mounting bolts.
(h) Check that the injectors rotate smoothly.
HINT: If injectors do not rotate smoothly, the probable cause
is incorrect installation of O±rings. Replace the O±rings.
(i) Position the injector connector outward.
(j) Tighten the four bolts holding the delivery pipes to the intake manifold.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
2. INSTALL FUEL RETURN PIPE
(a) Temporarily install the return pipe with the bolt, two
gaskets and union bolt.
(b) Tighten the union bolt holding the return pipe to the pressure regulator.
Torque: 35 N Vm (360 kgf Vcm, 26 ft Vlbf)
(c) Tighten the bolt holding the return pipe to the LH cylinder
head.
3. TIGHTEN LOCK NUT ON FUEL PRESSURE REGULATOR
Torque: 29 N Vm (300 kgf Vcm, 22 ft Vlbf)
FI±55EFI SYSTEM ± Fuel System (Injectors)
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Fuel Pressure Pulsation Damper
COMPONENTS FOR REMOVAL AND
INSTALLATION
FI±58 ± Fuel System (Fuel Pressure Pulsation Damper)EFI SYSTEM
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REMOVAL OF FUEL PRESSURE
PULSATION DAMPER
(See Component on page FI±58)
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. 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.
3. REMOVE LH ENGINE WIRE COVER Remove the two bolts and engine wire cover.
4. REMOVE FUEL PRESSURE PULSATION DAMPER (a) Remove the pulsation damper and upper gasket.
(b) Disconnect the fuel inlet hose from the delivery pipe,and remove the lower gasket. FI±59
EFI SYSTEM
± Fuel System (Fuel Pressure Pulsation Damper)
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INSTALLATION OF FUEL PRESSURE
PULSATION DAMPER
(See Components on page FI±58)
1. INSTALL FUEL PRESSURE PULSATION DAMPER Using SST, install two new gaskets, the inlet hose and pulsa-
tion damper.
SST 09612±24014 (09617±24011)
Torque: 39 N Vm (400 kgf Vcm, 29 ft Vlbf)
33 N Vm (340 kgf Vcm, 24 ft Vlbf) for SST
HINT: Use a torque wrench with a fulcrum length of 30 cm
(11.81 in.)
2. INSTALL LH ENGINE WIRE COVER
(a) Connect portions A and B engine wire cover to the wirebrackets.
(b) Set the VSV (for fuel pressure control system) wire in original position.
(c) Fit portions C and D of the engine wire cover, matching them with the lower high±tension cord cover and No.3
timing belt cover.
(d) Install the engine wire cover with the two bolts.
3. INSTALL UPPER HIGH±TENSION CORD COVER (a) Fit portion A of the upper high±tension cover, matching
it with the top of the lower high±tension cord cover.
(b) Push the front side of the high±tension cord cover, and connect the front side claw groove of the upper
high±tension cord cover to the claw of the lower
high±tension cord cover.
(c) Install the upper high±tension cord cover with the two bolts.
4. CONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
5. CHECK FOR FUEL LEAKS (See page FI±16)
FI±60
EFI SYSTEM
± Fuel System (Fuel Pressure Pulsation Damper)
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COMPONENTS
REMOVAL OF ISC VALVE
1. REMOVE LOWER HIGH±TENSION CORD COVER(See steps 1, 2 and 5 to 12 on pages FI±27 to 29)
2. REMOVE ISC VALVE
(a) Disconnect the ISC valve connector.
(b) (USA Spec.)Remove the bolt holding the water by±pass pipe (be-
tween ISC valve and EGR valve) to the air intake cham-
ber.
(c) (Exc. USA Spec.) Remove the bolt holding the water by±pass pipe (be-
tween ISC valve and EGR valve) to the VSV (for fuel
pressure control). FI±81
EFI SYSTEM
± Air Induction System (Idle Speed Control (ISC) Valve)
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INSTALLATION OF ISC VALVE
(See Components on page FI±81)
1. INSTALL ISC VALVE (a) Install a new gasket and the ISC valve with the two nuts.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
(b) Connect the following hoses to the ISC valve:
(1) Water by±pass hose (from throttle valve)
(2) Water by±pass hose (from water inlet housing)
(3) Water by±pass hose (from EGR valve)
(c) (USA Spec.) Install the vacuum pipe and water by±pass pipe (be-
tween ISC valve and EGR valve) to the air intake cham-
ber with the bolt.
(d) (Exc. USA Spec.) Install the water by±pass pipe (between ISC valve and
EGR valve) to the VSV (for fuel pressure control) with
the bolt.
(e) Connect the ISC valve connector.
1. INSTALL LOWER HIGH±TENSION CORD COVER (See steps 5 to 13 and 16 to 18 on pages FI±39 to 41)FI±83
EFI SYSTEM
± Air Induction System (Idle Speed Control (ISC) Valve)
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