Throttle Body: Service and Repair

CLEANING PROCEDURE

NOTE: Do not subject a throttle body assembly which contains the following components to an immersion cleaner or a strong solvent:
^ Throttle Position (TP) sensor
^ Idle Air Control (IAC) valve
^ Sealed throttle shaft bearings

The cleaners will damaged the electric components or sensors.

The cleaners will damage some of these components that contain seals or O-rings.

Solvents can wash away or break down the grease used on non-serviceable throttle shaft bearings.

Never use a wire brush or scraper to clean the throttle body. A wire brush or sharp tools may damage the throttle body components.

Do not use a cleaner that contains methyl ethyl ketone. This extremely strong solvent may damage components and is not necessary for this type of cleaning.

Clean the throttle body bore and the throttle plate on the vehicle using a clean shop towel with GM Top Engine Cleaner, P/N 1052626, or AC-Delco Carburetor Tune-Up Conditioner, P/N X66P, or equivalent. Remove and disassemble the throttle body for cleaning if the deposits are excessive. Refer to Idle Air Control (IAC) Valve Replacement for IAC valve removal and Throttle Position (TP) Sensor Replacement for TP sensor removal. After disassembly, clean the throttle body using a parts cleaner brush. DO NOT immerse the throttle body in any cleaning solvent.

An 8 digit part identification number is stamped on the bottom of the throttle body casting. Refer to this number if service or part replacement is required.

REMOVAL PROCEDURE

CAUTION: Refer to Battery Disconnect Caution in Service Precautions.




1. Disconnect the negative battery cable.
2. Remove the engine cover.
3. Remove the air cleaner outlet duct.
4. Remove the cruise control cable.




5. Remove the accelerator cable.




6. Remove the cruise control and accelerator cables and the mounting bracket.




7. Disconnect the IAC valve harness connector.




8. Disconnect the TP-sensor harness connector.




9. Remove the air cleaner adaptor stud.




10. Remove the throttle body fasteners.




11. Remove the throttle body assembly.
12. Remove and discard the flange seal.

INSTALLATION PROCEDURE




1. Clean the seal surface on the intake man fold.
2. Install a new flange seal.
3. Install the throttle body assembly.

NOTE: Refer to Fastener Notice in Service Precautions.




4. Install the throttle body assembly retaining fasteners.

Tighten
Tighten the fasteners to 25 N.m (18 lb ft).




5. Install the air cleaner adaptor stud.

Tighten
Tighten the stud to 8 N.m (72 lb in).




6. Connect the TP sensor harness connector.




7. Connect the IAC valve harness connector.




8. Install the accelerator and cruise control cables and the mounting bracket.

IMPORTANT: Make sure the accelerator and cruise control cables are properly routed. Improper routing may cause the throttle plate to remain open.




9. Install the accelerator cable.




10. Install the cruise control cable.
11. Install the air cleaner outlet duct.
12. Install the engine cover.
13. Connect the negative battery cable.

IMPORTANT: The accelerator pedal should operate freely without binding between closed and full throttle.

14. Depress and release the accelerator pedal in order to test for binding