Throttle Body: Service and Repair
REMOVAL1. DRAIN ENGINE COOLANT
2. REMOVE V-BANK COVER
a. Using a 5 mm hexagon wrench, remove the 3 cap nuts.
b. Loosen the V-bank cover fastener counterclockwise.
HINT: At the time of installation, please refer to the following items. Press down the V-bank cover fastener.
c. Remove the V-bank cover.
3. REMOVE AIR CLEANER HOSE WITH RESONATOR
a. Disconnect the PCV hose.
b. Disconnect the vacuum hose (from the VSV for the active engine control mount).
c. Loosen the 3 hose clamps, and remove the air cleaner hose with the resonator.
4. DISCONNECT ACCELERATOR CABLE AND THROTTLE CABLE
5. REMOVE THROTTLE BODY
a. Remove the bolt holding the throttle body to the throttle body bracket.
Torque: 19.5 N.m (200 kgf.cm, 14 ft.lbf)
b. Disconnect the throttle position sensor connector.
c. Disconnect the IAC valve connector.
d. Disconnect the wire clamp.
e. Disconnect the brake booster vacuum hose.
f. Disconnect the water bypass hose (from the intake manifold).
g. Disconnect the water bypass hose (from the water inlet housing).
h. Disconnect the air assist hose.
i. Disconnect the fuel vapor feed hose (from the emission control valve set).
j. Disconnect the vacuum hose (from the No.1 ACIS VSV).
k. Disconnect the vacuum hose (from the vacuum tank for the ACIS).
l. Remove the 3 nuts, throttle body and gasket.
HINT: At the time of installation, please refer to the following items. Place a new gasket on the air intake chamber.
Torque: 29 N.m (300 kgf.cm, 22 ft.lbf)
INSPECTION
NOTE: In case of changing, removing or installing the throttle body or IAC valve, must do this.
1. INSPECT THROTTLE BODY
a. Check that there is no clearance between each throttle stop screw and the throttle lever when applying the vacuum (53.3 kPa (400 mm.Hg, 15.7 in.Hg)) to the throttle opener using a MITYVAC (hand-held Vacuum Pump).
Standard: Must have no clearance
NOTE: As the throttle stop screw is precisely adjusted, so do not adjust it.
b. Under the condition of (1), check visually that there is a clearance between each adjust screw and the throttle lever on No.1 side.
c. Measure the clearance between the adjust screw on the close side when fully opening the throttle lever on No.2 side by hand and the throttle lever on No.1 side with a feeler gauge.
Standard value: 0.25 - 0.45 mm (0.0098 - 0.0177 in.)
In case of being out of standard value, perform the adjustment of step 2.
2. ADJUST THROTTLE BODY (BALANCE)
NOTE: Do not adjust the throttle stop screw and throttle opener.
a. Beforehand checking.
Recheck 1 - (a).
b. Adjustment of the adjust screw on the open side.
1. Using a 2 mm hexagon wrench, loosen the lock nut and screw, make clearance between the screw tip and the throttle lever on No.1 side.
2. Turn the screw to the screw torque direction gradually, and stop it at the position where to touch the lever at the very moment.
NOTE: If turning it too much to the torque direction, the No.1 lever goes off from the throttle stop screw causing the adjustment failure.
3. Turn it back from the position where it touches the lever to the screw loosing direction.
Standard: Turn it back by rotating 1/4
4. Tighten the lock nut.
c. Adjustment of the adjust screw on the close side.
1. Loosen the lock nut and screw, and make clearance between the screw tip and the throttle lever on No.1 side.
2. Turn the screw to the screw torque direction gradually, and stop it at the position where to touch the lever at the very moment.
NOTE: If turning it too much to the torque direction, the No.2 lever goes off from the throttle stop screw causing the adjustment failure.
3. Turn it back from the position where it touches the lever to the screw loosing direction.
Standard: Turn it back by rotating 1/2 - 3/4
4. Tighten the lock nut.
d. Completion checking.
Check 1 - (c).
REPLACEMENT
NOTE:
- Do not give a shock to the throttle position senor.
- Do not disassemble or adjust the throttle opener.
1. REPLACE THROTTLE POTION SENSOR
a. Remove the 2 screws and throttle position sensor.
b. Reinstall a new throttle position sensor.
1. Check that the throttle valve is fully close.
2. Insert the sensor to the throttle body with it turned counterclockwise by 30° to 60° against the fully close valve position.
3. By turning the sensor clockwise, tighten the 2 screws.
2. REPLACE IAC VALVE
a. Remove the 4 screws, bracket, IAC valve and gasket.
b. Place a new gasket on the No.1 throttle body.
c. Reinstall a new IAC valve with the 4 screws and bracket.
3. REPLACE THROTTLE BODIES
a. Remove the 2 screws and protector.
b. Remove the 6 screws, No.1 throttle body, No.2 throttle body and 2 gaskets from the No.1 intake air control valve.
c. Place 2 new gaskets and 2 new O-rings as shown in the illustration.
d. Reinstall a new No.1 throttle body and No.2 throttle body with the 6 screws.
Torque: 6.9 N.m (70 kgf.cm, 61 in.lbf)
INSTALLATION
Installation is in the reverse order of removal.