Lexus SC300 / Lexus SC400. Manual - part 421

(b)  Install a new gasket and throttle body with the two bolts

and two nuts.

Torque: 18 N

⋅

m (185 kgf

⋅

cm, 13 ft

⋅

lbf)

HINT: Use bolts 40 mm (1.57 in.) in length.
(c)  Install the water by–pass pipe (from rear water by–pass

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

(e)  Connect the following connectors:

(1)

Throttle position sensor connector

(2)

(w/ TRAC)
Sub–throttle position sensor connector

(3)

(w/ TRAC)
Sub–throttle actuator

27. REINSTALL 

HEATER 

WATER 

VALVE

(a)  Install the water valve and bracket assembly with the

two bolts.

(b)  Install the engine wire clamp with the bolt.
(c)  Connect the VSV connector.

EM–24

–

ENGINE MECHANICAL

Engine Tune–Up

28.  REINSTALL RH NO.3 TIMING BELT COVER

(a)  Install the three gaskets to the timing belt cover.
(b)  Fit portion A of the timing belt cover, matching it with the

lower high–tension cord cover.

(c)  Install the timing belt cover with the three bolts.

29.  REINSTALL VSV FOR EVAP SYSTEM

Install the VSV with the two bolts.

30.  REINSTALL 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 three bolts.

31.  RECONNECT PCV HOSE TO LH CYLINDER HEAD
32.  RECONNECT FUEL RETURN HOSE TO FUEL RETURN

PIPE

33.  RECONNECT FUEL INLET HOSE TO LH DELIVERY PIPE

Connect the inlet hose with two new gaskets and the 
pulsation damper.
SST 09612–24014 (09617–24011)

Torque: 39 N

⋅

m (400 kgf

⋅

cm, 29 ft

⋅

lbf)

33 N

⋅

m (340 kgf

⋅

cm, 24 ft

⋅

lbf) for SST

HINT: Use a torque wrench with a fulcrum length of 30 cm
(11.81 in.)

34.  REINSTALL 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.

(b)  Install the engine wire cover with the bolt.

–

ENGINE MECHANICAL

Engine Tune–Up

EM–25

35.  REINSTALL LH ENGINE WIRE COVER

(a)  Connect portions A and B engine wire cover to the wire

brackets.

(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.

36.  REINSTALL UPPER HIGH–TENSION CORD COVER

(a)  Fit portion A of the upper high–tension cover, matching

the top of the lower high–tension cord cover.

(b)  Push the front side of the upper 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.

37.  REINSTALL INTAKE AIR CONNECTOR

(a)  Connect the end portions of the intake air connector to

the 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 to ISC valve

(2)

Air hose (from PS air control valve) to intake air 
connector

EM–26

–

ENGINE MECHANICAL

Engine Tune–Up

38.  RECONNECT CONTROL CABLES TO THROTTLE BODY

Connect the following hoses:

(1)

Accelerator cable

(2)

A/T throttle control cable

(3)

(w/ Cruise Control System)
Cruise control actuator cable

39.  REINSTALL THROTTLE BODY COVER

Install the throttle body cover and hose clamp with the two
bolts and cap nut.

40. RECONNECT CABLE TO NEGATIVE TERMINAL OF

BATTERY

41.  FILL WITH ENGINE COOLANT (See page 

CO–7

)

INSPECTION OF IGNITION TIMING

(See page 

IG–28

)

Ignition timing:

8–12

°

 BTDC @ idle

(w/ Terminals TE1 and E1 connected)

INSPECTION OF IDLE SPEED

HINT:

•

Initial conditions (See step 1 on page 

EM–28

)

•

Set the tachometer to the 4–cylinder range.

Idle speed: 700 

±

 50 rpm

–

ENGINE MECHANICAL

Engine Tune–Up

EM–27