GM Service Manual Online
For 1990-2009 cars only

    Object Number: 1639213  Size: SH
  1. Remove the throttle body bolts and nuts.
  2. Remove the throttle body.
  3. Remove the throttle body studs, if required.
  4. Remove the manifold absolute pressure (MAP) sensor (1).
  5. Remove the evaporative emission (EVAP) purge valve bolt (2).
  6. Remove the EVAP purge valve (3).

  7. Object Number: 1665698  Size: SH
  8. Remove the EVAP purge valve isolator, if equipped.

  9. Object Number: 1557831  Size: SH

    Important: If at any time the intake manifold tuning valve blade becomes separated from the actuator, DO NOT cycle the actuator. Cycling the actuator without the blade attached will offset the calibration, and the entire intake manifold tuning valve assembly will need to be replaced.

  10. Remove the intake manifold tuning valve bolts.
  11. Remove the intake manifold tuning valve.
  12. Caution: Bodily injury may occur if the cleaning solvent is inhaled or exposed to the skin.

  13. Clean the intake manifold with solvent.
  14. Dry the intake manifold with compressed air.
  15. Inspect all gasket mating surfaces for nicks or cracks and replace if necessary.
  16. Inspect the intake manifold tuning valve seal for damage. Inspect the intake manifold tuning valve blade for cracks, missing material, or looseness. The tuning valve blade attachment to the motor should be tight, with no slack present. Replace if necessary.

  17. Object Number: 1580024  Size: SH
  18. Apply lubricant GM P/N 1051344 (Canadian P/N 993037) to the valve shaft (1).

  19. Object Number: 1557831  Size: SH
  20. Install the intake manifold tuning valve, ensuring proper alignment is achieved. Failure to do so may result in the valve getting jammed or stuck in the intake manifold.
  21. 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.

  22. Install the intake manifold tuning valve bolts.
  23. Tighten
    Tighten the intake manifold tuning valve bolts to 10 N·m (89 lb in).


    Object Number: 1665698  Size: SH
  24. Install the EVAP purge valve isolator, if equipped.

  25. Object Number: 1639213  Size: SH
  26. Inspect the EVAP purge valve seal for damage and replace if necessary.
  27. Install the EVAP purge valve (3).
  28. Install the EVAP purge valve bolt (2).
  29. Tighten
    Tighten the EVAP purge valve bolt to 16 N·m (12 lb ft).


    Object Number: 1665700  Size: SH

    Important: Ensure that the EVAP purge valve isolator is installed properly as shown, with the isolator covering the top and bottom of the purge valve bolt hole flange. Failure to do so may cause improper EVAP purge valve operation.

  30. Inspect the MAP sensor seal for damage and replace if necessary.
  31. Install the MAP sensor.
  32. Install the throttle body studs, if required.
  33. Tighten
    Tighten the throttle body studs to 6 N·m (53 lb in).

  34. Inspect the throttle body seal for damage and replace if necessary.
  35. Install the throttle body.
  36. Apply threadlock GM P/N 12345382 (Canadian P/N 10953489) to the throttle body bolt and nut threads.
  37. Install the throttle body bolts and nuts.
  38. Tighten
    Tighten the throttle body bolts and nuts to 10 N·m (89 lb in).