GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Open the hood.
  2. Remove the air cleaner layer. Refer to Air Cleaner Replacement .

  3. Object Number: 652573  Size: SH
  4. Remove the air intake pipe. Refer to Air Intake Pipe Replacement .
  5. Disconnect the air conditioning (A/C) compressor clutch electrical connector.
  6. Disconnect the A/C cut out switch electrical connector.
  7. Remove the drive belt. Refer to Drive Belt Replacement in Engine Mechanical - 6.6L.
  8. Remove the A/C compressor bolts.
  9. Move the A/C compressor with the hoses attached to the right side of the engine compartment.

  10. Object Number: 674653  Size: SH
  11. Remove the water outlet tube. Refer to Water Outlet Tube Replacement in Engine Cooling.
  12. Disconnect both main harness electrical connectors.

  13. Object Number: 674680  Size: SH
  14. Remove both main harness electrical connector to bracket bolts (1).
  15. Remove the main harnesses from the bracket.

  16. Object Number: 740506  Size: SH
  17. Disconnect the engine coolant temperature (ECT) sensor electrical connector (1).

  18. Object Number: 739503  Size: SH
  19. Disconnect the barometric pressure (BARO) sensor electrical connector (1)

  20. Object Number: 786978  Size: SH
  21. Disconnect the glow plug relay electrical connectors (1, 2, 3).

  22. Object Number: 786977  Size: SH
  23. Disconnect the fuel rail temperature sensor electrical connector (1).

  24. Object Number: 786986  Size: SH
  25. Disconnect the left front fuel injector electrical connector (1).

  26. Object Number: 786988  Size: SH
  27. Disconnect the left rear fuel injector electrical connector (1).

  28. Object Number: 786996  Size: SH
  29. Disconnect the fuel pressure regulator electrical connector (1).

  30. Object Number: 788846  Size: SH
  31. Disconnect the oil level sensor harness electrical connector (1).

  32. Object Number: 687021  Size: SH
  33. Remove the positive crankcase ventilation (PCV) hose from both valve covers.

  34. Object Number: 901298  Size: SH
  35. Reposition the injection pump inlet clamp.
  36. Remove the injection pump inlet hose from the fuel feed distribution (leak-off) block. Reposition the hose.

  37. Object Number: 901300  Size: SH
  38. Clean the fuel pressure regulator and high pressure injection pump thoroughly with solvent, such as GM P/N 12377981 (Canadian P/N 10953463) or equivalent.
  39. Using compressed air, thoroughly blow dry the regulator and pump.
  40. Remove the 3 fuel pressure regulator screws (1) using a T25 TORX®.

  41. Object Number: 901301  Size: SH
  42. Remove the fuel pressure regulator (1).
  43. If dirt or debris is found in the bore or seating surfaces of the fuel injection pump, perform the following:
  44. • Place a clean rag over the bore on order to collect the excess fuel.
    • Bump the engine over in order to flush any debris out of the regulator bore.

Installation Procedure

Important: If the pressure regulator is being re-used, check the O-rings for damage. If the O-rings are damaged, install NEW O-rings.


    Object Number: 901301  Size: SH
  1. Lubricate and install NEW O-rings onto the regulator. Lubricate the O-rings with clean, NEW engine oil.
  2. Important: If the regulator is installed at an angle the O-rings may be damaged, resulting in possible fuel leakage.

  3. Install the fuel pressure regulator (1).
  4. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 901300  Size: SH
  5. Install the 3 fuel pressure regulator screws (1) using a T25 TORX®.
  6. Tighten

        • Tighten the screws a first pass to 4 N·m (35 lb in).
        • Tighten the screws a final pass to 7 N·m (62 lb in).

    Object Number: 901298  Size: SH
  7. Install the injection pump inlet hose to the fuel feed distribution (leak) block.
  8. Position the injection pump inlet clamp.

  9. Object Number: 687021  Size: SH
  10. Install the PCV hose to both valve covers.

  11. Object Number: 788846  Size: SH
  12. Connect the oil level sensor harness electrical connector (1).

  13. Object Number: 786996  Size: SH
  14. Connect the fuel pressure regulator electrical connector (1).

  15. Object Number: 786988  Size: SH
  16. Connect the left rear fuel injector electrical connector (1).

  17. Object Number: 786986  Size: SH
  18. Connect the left front fuel injector electrical connector (1).

  19. Object Number: 786977  Size: SH
  20. Connect the fuel rail temperature sensor electrical connector (1).

  21. Object Number: 786978  Size: SH
  22. Connect the glow plug relay electrical connectors (1, 2, 3).

  23. Object Number: 739503  Size: SH
  24. Connect the BARO sensor electrical connector (1)

  25. Object Number: 740506  Size: SH
  26. Connect the ECT sensor electrical connector (1).

  27. Object Number: 674680  Size: SH
  28. Install the main harnesses to the bracket.
  29. Install both main harness electrical connector to bracket bolts (1).
  30. Tighten
    Tighten the bolts to 21 N·m (15 lb ft).


    Object Number: 674653  Size: SH
  31. Connect both main harness electrical connectors.
  32. Install the water outlet tube. Refer to Water Outlet Tube Replacement in Engine Cooling.

  33. Object Number: 652573  Size: SH
  34. Position the A/C compressor.
  35. Install the A/C compressor bolts.
  36. Tighten
    Tighten the bolts to 53 N·m (37 lb ft).

  37. Install the drive belt. Refer to Drive Belt Replacement in Engine Mechanical - 6.6L.
  38. Connect the A/C cut out switch electrical connector.
  39. Connect the A/C compressor clutch electrical connector.
  40. Install the air intake pipe. Refer to Air Intake Pipe Replacement .
  41. Install the air cleaner layer, Refer to Air Cleaner Replacement .
  42. Close the hood.