GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 S10 Pickup - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Throttle Body Assembly Replacement

Cleaning Procedure

Notice: 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 damage 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 throttle valve 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 if the deosits are excessive. Refer to Idle Air Control Valve Replacement

for IAC removal or

Throttle Position Sensor Replacement

for TP sensor removal. After disassembly, clean the throttle body using a parts cleaning brush. DO NOT immerse the throttle body in any cleaning solvent.

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.

    2. Object Number: 10940 Size: SH
  2. Disconnect the IAT sensor harness connector.

    3. Object Number: 309177 Size: SH
  3. Disconnect the breather tube from the air cleaner outlet duct.

    4. Object Number: 312278 Size: SH
  4. Remove the air cleaner outlet duct retaining wing nut.

    5. Object Number: 424556 Size: SH
  5. Loosen the clamp on the outlet of the MAF sensor.
  6. Lift the air cleaner outlet duct from the throttle body and remove the assembly from the MAF sensor.

    7. Object Number: 424550 Size: SH
  7. Remove the air cleaner outlet adapter stud.

    8. Object Number: 325550 Size: SH
  8. Disconnect the cruise control cable from the throttle body.

    9. Object Number: 325556 Size: SH
  9. Disconnect the accelerator cable from the throttle body.

    10. Object Number: 424533 Size: SH
  10. Remove the nuts retaining the accelerator cable routing bracket and position bracket aside.

    11. Object Number: 424537 Size: SH
  11. Remove the stud and nuts retaining the accelerator control cable bracket and position bracket aside.

    12. Object Number: 312513 Size: SH
  12. Disconnect the IAC valve harness connector.

    13. Object Number: 12885 Size: SH
  13. Disconnect the TP sensor harness connector.

    14. Object Number: 12852 Size: SH
  14. Remove the throttle body retaining studs.

    15. Object Number: 12853 Size: SH
  15. Remove the throttle body assembly.
  16. Discard the throttle body seal.

Installation Procedure

    Object Number: 12853 Size: SH
  1. Clean the seal surface on the intake manifold.
  2. Install the throttle body assembly with a new flange seal.

    3. Object Number: 12852 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Install the throttle body assembly retaining studs.

    4. Tighten
    Tighten the studs to 9 N·m (80 lb in).


    Object Number: 424537 Size: SH
  4. Install the accelerator control cable bracket using the mounting stud and nuts.

    5. Tighten
    Tighten the stud and nuts to 12 N·m (108 lb in).


    Object Number: 424533 Size: SH
  5. Install the accelerator cable routing bracket using the mounting nuts.

    6. Tighten
    Tighten the accelerator cable routing bracket nuts to 9 N·m (75 lb in).


    Object Number: 12885 Size: SH
  6. Connect the TP sensor harness connector.

    7. Object Number: 312513 Size: SH
  7. Connect the IAC valve harness connector.

    8. Object Number: 325556 Size: SH

    Important: The accelerator pedal should operate freely without binding between closed and wide open throttle.

  8. Install the accelerator cable onto the throttle body.

    9. Object Number: 325550 Size: SH
  9. Install the cruise control cable onto the throttle body..

    10. Object Number: 424550 Size: SH
  10. Install the air cleaner outlet duct adapter stud.

    11. Tighten
    Tighten the studs to 8 N·m (72 lb in).


    Object Number: 424556 Size: SH
  11. Connect the clamp on the outlet of the MAF sensor
  12. Install the air cleaner outlet duct on the throttle body and install the assembly on the MAF sensor.

    13. Tighten
    Tighten the clamp to 4 N·m (35 lb in).


    Object Number: 312278 Size: SH
  13. Install the air cleaner outlet duct retaining wing nut.

    14. Tighten
    Tighten the wingnut to 2 N·m (18 lb in).


    Object Number: 309177 Size: SH
  14. Connect the breather tube from the air cleaner outlet duct.
  15. Connect the negative battery cable.