Lexus SC300 / Lexus SC400. Manual - part 614

C. Inspect 

sub–throttle 

valve

Check that there is no clearance between the throttle stop
screw and throttle valve gear when the sub–throttle valve is
fully closed.

D.  Inspect sub–throttle position sensor

(a) Insert 

a 

0.30 mm (0.012 in.) or 0.50 mm (0.020 in.) feeler

gauge between the throttle stop screw and throttle valve
gear.

(b)  Using an ohmmeter, measure the resistance between

each terminal.

Clearance between

lever and stop screw

Between terminals

Resistance

0 mm (0 in.)

VTA2–E2

0.2–0.8 

0.30 mm (0.012 in.)

IDL2–E2

2.3 k

 or less

0.50 mm (0.020 in.)

IDL2–E2

Infinity

Throttle valve fully
open

VTA2–E2

3.3–10.0 k

–

VC–E2

4.0–9.0 k

E. 

If necessary, adjust sub–throttle position sensor
(a)  Loosen the two set screws of the sensor.

(b)  Insert a 0.30 mm (0.012 in.) feeler gauge, between the

throttle stop screw and throttle valve gear.

(c)  Connect the test probe of an ohmmeter to the terminals

IDL2 and E2 of the sensor.

FI–75

EFI SYSTEM   –   Air Induction System (Throttle Body)

(d)  Gradually turn the sensor clockwise until the ohmmeter

deflects, and secure it with the two set screws.

(e)  Recheck the continuity between terminals IDL2 and E2.

Clearance between

lever and stop screw

Continuity (IDL2–E2)

0.30 mm (0.012 in.)

Continuity

0.50 mm (0.020 in.)

No continuity

E.  Reinstall sub–throttle actuator

Install the sub–throttle actuator with the three screws.

FI–76

EFI SYSTEM   –   Air Induction System (Throttle Body)

INSTALLATION OF THROTTLE BODY

(See Components o page 

FI–69

)

1. 

INSTALL THROTTLE BODY
(a)  Install the two water by–pass hoses and pipe to the

throttle body.

(b)  Connect the following hoses:

(1)  PCV hose to throttle body
(2)  Water by–pass hose to throttle body

(c)  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.
(d)  Install the water by–pass pipe (from rear water by–pass

joint) to the clamp on the engine wire cover.

(e)  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–77

EFI SYSTEM   –   Air Induction System (Throttle Body)

(4) Heater water hose to heater water valve

(f)  Connect the following connectors:

(1)  Throttle position sensor connector
(2) (w/ 

TRAC)

Sub–throttle position sensor connector

(3) (w/ 

TRAC)

Sub–throttle actuator connector

2. 

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.

3. 

INSTALL 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.

FI–78

EFI SYSTEM   –   Air Induction System (Throttle Body)