1991 LEXUS SC400 fuel pressure

4. CONNECT CONNECTORSConnect the following connectors:w Cold start injector connector
w ISC valve connector
w (USA Spec.)
EGR valve connector
w (Exc. USA Spec.)
VSV connector for EGR system
w SV connector for fuel pressure control system
5. INSTALL THROTTLE BODY (a) Connect the following hoses:(1) PCV hose to throttle body
(2) Water by±pass hose to throttle body
(b) Install a new gasket and throttle body with the two bolts and two nuts.
Torque: 18 N Vm (185 kgf Vcm, 13 ft Vlbf)
HINT: Use bolts 40 mm (1.57 in.) in length.
(c) Install the water by±pass pipe (from rear water bypass
joint) to the clamp on the engine wire cover.
(d) Connect the following hoses: (1) Water by±pass hose to the ISC valve
(2) (USA Spec.) Vacuum hose to throttle body
(3) (Exc. USA Spec.) Three vacuum hoses to throttle body
FI±38
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName

8. INSTALL VSV FOR EVAP SYSTEMInstall the VSV with the two bolts.
9. INSTALL LH NO.3 TIMING BELT COVER (a) Install the three gaskets to the timing belt cover.
(b) Install the cord grommet to the high±tension cord.
(c) Install the cord grommet to the timing belt cover.
(d) Fit portion A of the timing belt cover, matching it with the
lower high±tension cord cover.
(e) Install the timing belt cover with the four bolts.
10. INSTALL RH ENGINE WIRE COVER (a) Fit portions A and B 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 bolt.
11. 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.
12. 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.
FI±40
EFI SYSTEM
± Fuel System (Cold Start Injector)
WhereEverybodyKnowsYourName

Fuel Pressure Regulator
ON±VEHICLE INSPECTION
INSPECT FUEL PRESSURE (See page FI±18)
FI±42
± Fuel System (Fuel Pressure Regulator)EFI SYSTEM
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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

(b) Remove the bolt holding the intake air connector to thecylinder 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.
3. REMOVE UPPER HIGH±TENSION CORD COVER (a) Remove the two mounting bolts.
(b) Disconnect the front side claw groove of the cord cover
from the claw of the lower cover, and remove the cord
cover.
4. REMOVE RH ENGINE WIRE COVER Remove the bolt and wire cover.
5. DISCONNECT VACUUM SENSING HOSE FROM FUEL PRESSURE REGULATOR
FI±44
EFI SYSTEM
± Fuel System (Fuel Pressure Regulator)
WhereEverybodyKnowsYourName

6. DISCONNECT FUEL RETURN PIPE FROM FUELPRESSURE REGULATOR
Remove the union bolt and two gasket, and disconnect the
return pipe from the pressure regulator.
HINT:
wPut a suitable container or shop towel under the
pressure regulator.
w Slowly loosen the union bolt.
7. REMOVE FUEL PRESSURE REGULATOR (a) Loosen the lock nut.
(b) Lift up the water by±pass hose between the ISC valveand throttle body, and remove the pressure regulator.
(c) Remove the O±ring from the pressure regulator.
INSTALLATION OF FUEL PRESSURE
REGULATOR
(See components on page FI±43)
1. INSTALL FUEL PRESSURE REGULATOR AND FUEL RETURN PIPE
(a) Fully loosen the lock nut on the pressure regulator.
(b) Apply a light coat of gasoline to a new O±ring, and install
it to the pressure regulator.
(c) Lift up the water by±pass hose between the ISC valve and throttle body, and completely insert the pressure
regulator into the delivery pipe by hand.
(d) Turn the pressure regulator counterclockwise until the vacuum sensing port faces in the direction indicated in
the illustration. FI±45
EFI SYSTEM
± Fuel System (Fuel Pressure Regulator)
WhereEverybodyKnowsYourName

(e) Connect the fuel return pipe to the pressure regulatorwith new two gaskets and the union bolt.
Torque: 35 N Vm (360 kgf Vcm, 26 ft Vlbf)
(f) Tighten the lock nut.
Torque: 29 N Vm (300 kgf Vcm, 22 ft Vlb)
2. CONNECT VACUUM SENSING HOSE TO FUEL
PRESSURE REGULATOR
3. INSTALL RH ENGINE WIRE COVER (a) Fit portions A and B of the engine wire cover, matchingthem with the lower high±tension cord cover and No.3
timing belt cover.
(d) Install the engine wire cover with the bolt.
FI±46
EFI SYSTEM
± Fuel System (Fuel Pressure Regulator)
WhereEverybodyKnowsYourName

4. INSTALL UPPER HIGH±TENSION CORD COVER(a) Fit portion A of the upper high±tension cover, matchingit 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.
5. INSTALL INTAKE AIR CONNECTOR (a) Connect the end portions of the intake air connector tothe throttle body and air cleaner hose.
(b) Tighten the two hose clamps.
(c) Install the bolt holding the intake air connector to the
cylinder head cover.
(d) Connect the following hoses: (1) Air hose to ISC valve
(2) Air hose (from PS air control valve) to intake air con-
nector
6. CONNECT CABLE TO NEGATIVE TERMINAL OF BATTERY
7. CHECK FOR FUEL LEAKS (See page FI±16) FI±47
EFI SYSTEM
± Fuel System (Fuel Pressure Regulator)
WhereEverybodyKnowsYourName