Lexus SC300 / Lexus SC400. Manual - part 520

Fuel Pressure Regulator

ON–VEHICLE INSPECTION

INSPECT FUEL PRESSURE (See page 

FI–18

)

FI–42

              –   Fuel System (Fuel Pressure Regulator)

EFI SYSTEM

COMPONENTS FOR REMOVAL AND
INSTALLATION

REMOVAL OF FUEL PRESSURE
REGULATOR

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 ”LOCK” 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)

(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.

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

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EFI SYSTEM   –   Fuel System (Fuel Pressure Regulator)

6. DISCONNECT 

FUEL 

RETURN 

PIPE 

FROM 

FUEL

PRESSURE REGULATOR
Remove the union bolt and two gasket, and disconnect the
return pipe from the pressure regulator.
HINT:

•

Put a suitable container or shop towel under the
pressure regulator.

•

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 valve

and 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)