GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Riviera 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 Throttle Body Assembly Replacement

Removal Procedure

    Object Number: 49593 Size: SH
  1. Drain the radiator coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Remove the fuel injection sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical.

    3. Object Number: 179039 Size: SH
  3. Remove the IAT sensor electrical connector (1) from the IAT sensor (2).

    4. Object Number: 210987 Size: SH
  4. Remove the intake air duct from the throttle body.

    5. Object Number: 155466 Size: SH
  5. Remove the IAC valve electrical connector from the IAC valve.

    6. Object Number: 178680 Size: SH
  6. Remove the TP sensor electrical connector from the TP sensor.

    7. Object Number: 155464 Size: SH
  7. Remove the MAF sensor electrical connector from the MAF sensor.

    8. Object Number: 179339 Size: SH
  8. Remove the cruise control cable (1) from the accelerator controls bracket (2). Refer to Cruise Control Cable Replacement in Cruise Control.

    9. Object Number: 179152 Size: SH
  9. Remove the accelerator control cable (1) from the accelerator control bracket (2). Refer to Accelerator Control Cable Replacement .

    10. Object Number: 179147 Size: SH
  10. Remove the cruise control cable (2) from the throttle body lever (3). Refer to Cruise Control Cable Replacement.

    11. Object Number: 179148 Size: SH
  11. Remove the accelerator control cable (2) from the throttle body lever (3). Refer to Accelerator Control Cable Replacement .

    12. Object Number: 179374 Size: SH
  12. Remove the electrical harness (2) retainer clip (1) from the accelerator control cable bracket (3) if applicable.

    13. Object Number: 12246 Size: SH
  13. Remove the accelerator control cable bracket, if replacing throttle body.

    14. Object Number: 203948 Size: SH
  14. Remove the nuts and bolts holding the throttle body to the intake manifold using a wrench on the manifold side of the inserts to prevent the inserts from rotating in the manifold casting.
  15. Remove the throttle body assembly.

    16. Notice: Do not use solvent of any type when cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as damage to the gasket surfaces and throttle body assembly may result.

    Use care in cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as sharp tools may damage the gasket surfaces.

  16. Clean the gasket surface on the intake manifold and the throttle body assembly.

Installation Procedure

    Object Number: 12246 Size: SH
  1. Install the accelerator controls cable bracket to the throttle body if necessary.

    2. Tighten
    Tighten the bolts to 16 N·m  (12 lb ft).


    Object Number: 203948 Size: SH
  2. Install the new gasket, and new inserts and studs if necessary.
  3. Install the throttle body assembly.
  4. Install the throttle body retaining nuts and bolts.

    5. Tighten
    Tighten the throttle body retaining nuts and bolts to 10 N·m  (7 lb ft).


    Object Number: 179374 Size: SH
  5. Install the electrical harness (2) retainer clip (1) from the accelerator control cable bracket (3) if applicable.

    6. Object Number: 179152 Size: SH
  6. Install the accelerator control cable (1) to accelerator control bracket (2) at the throttle body.

    7. Object Number: 179339 Size: SH
  7. Install the cruise control cable (1) to accelerator control bracket at the throttle body (2).

    8. Object Number: 179148 Size: SH

    Important: The throttle should operate freely without binding between full closed and wide open throttle. Refer to Accelerator Control Cable Replacement .

  8. Install the accelerator control cable (2) to the throttle body lever (3).

    9. Object Number: 179147 Size: SH
  9. Install the cruise control cable (2) to the throttle body lever (3).
  10. Check for complete throttle opening and closing positions by operating the accelerator pedal.
  11. Check for poor carpet fit under the accelerator pedal.

    12. Object Number: 179374 Size: SH
  12. Install the electrical harness (2) retainer clip (1) and harness to the accelerator control bracket (3) if applicable.

    13. Object Number: 180061 Size: SH
  13. Install the vacuum line to throttle body (1).

    14. Object Number: 155464 Size: SH
  14. Install the MAF sensor electrical connector to the MAF sensor.

    15. Object Number: 178680 Size: SH
  15. Install the TP sensor electrical connector to the TP sensor.

    16. Object Number: 155466 Size: SH
  16. Install the IAC valve electrical connector to the IAC valve.

    17. Object Number: 210987 Size: SH
  17. Install the intake air duct from the throttle body.

    18. Object Number: 179039 Size: SH
  18. Install the IAT (Intake Air Temperature) Sensor electrical connector (1) from the IAT Sensor (2).

    19. Object Number: 49593 Size: SH
  19. Refill the radiator to replace the lost coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  20. Install the fuel injection sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical.

    21. Tighten
    Tighten the fuel injection sight shield nut to 2 N·m  (18 lb in).