GM Service Manual Online
For 1990-2009 cars only

Fuel Injection Fuel Rail Assembly Replacement 4.6

Removal Procedure

Tools Required

Refer to J 41081 Injector Remover, J 37088-A Fuel Line Quick-Connect Separator

Notice: 

   • Remove the fuel rail assembly carefully in order to prevent damage to the injector electrical connector terminals and the injector spray tips. Support the fuel rail after the fuel rail is removed in order to avoid damaging the fuel rail components.
   • Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering open pipes and passages.


    Object Number: 41528  Size: SH
  1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure .
  2. Remove the intake air duct clamp from the air cleaner assembly.
  3. Remove the intake air duct clamp from the MAF Sensor
  4. Remove the EGR pipe and crankcase ventilation pipe at throttle body spacer.
  5. Remove the brake booster vacuum hose at intake manifold.
  6. Remove the front bank spark plug wires.
  7. Remove the injector harness electrical connector.
  8. Remove transaxle vent hose from clip.

  9. Object Number: 20434  Size: SH
  10. Remove the fuel pressure regulator vacuum line.
  11. Disconnect the quick-connect fittings at fuel rail.
  12. Grasp both sides of fitting.

  13. Object Number: 20450  Size: SH
  14. Remove the fuel rail ground wire (1) at rear cylinder head.

  15. Object Number: 12775  Size: SH
  16. Twist the female connector 1/4 turn in each direction to loosen any dirt within fitting.

  17. Object Number: 12776  Size: SH

    Caution: Wear safety glasses when using compressed air in order to prevent eye injury.

  18. Blow dirt out of fitting using compressed air.
  19. Choose correct tool from J 37088-A tool set for size of fitting.

  20. Object Number: 12780  Size: SH
  21. Insert tool into female connector, then push/pull inward to release locking tabs.

  22. Object Number: 12780  Size: SH

    Notice: Use an emery cloth in order to remove rust or burrs from the fuel pipe. Use a radial motion with the fuel pipe end in order to prevent damage to the O-ring sealing surface.

  23. Pull connection apart.

  24. Object Number: 18881  Size: SH
  25. Disconnect fuel pipe bracket at EGR valve.
  26. Remove throttle body mount bolts.
  27. Release locking tabs on fuel rail and pry each injector out of intake manifold using J 41081.
  28. Remove the fuel rail assembly.

Disassemble Procedure


    Object Number: 20453  Size: SH
  1. Remove the injector harness.
  2. Remove the injector(s) (12) from the fuel rail.
  3. Remove the upper (11) and lower (13) O-rings from injectors.
  4. Discard the O-rings.
  5. Clean the throttle body O-ring surfaces.

Assemble Procedure


    Object Number: 20453  Size: SH
  1. Lubricate the new upper (11) and lower (13) injector O-rings with clean engine oil and install on injectors.
  2. Install the injectors to fuel rail with new retainer clip(s).
  3. 2.1. Ensure injectors are aligned by orientating electrical connector perpendicular to crankshaft.
  4. Install the injector harness.

Installation Procedure


    Object Number: 18881  Size: SH
  1. Install the fuel rail with injectors to intake manifold.

  2. Object Number: 19023  Size: SH
  3. Install the new throttle body spacer gasket (2), throttle body spacer (3), and mount bolts.
  4. Tighten
    Tighten the throttle body spacer bolts to 12 N·m (106 lb in).

  5. Install the new throttle body gasket, throttle body, and bolts.
  6. Tighten
    Tighten the throttle body bolts to 12 N·m (106 lb in).


    Object Number: 12784  Size: SH
  7. Apply a few drops of clean engine oil to the male ends of the engine fuel rail inlet and outlet pipes.
  8. Install the quick-connect fittings to fuel rail:

  9. Object Number: 12786  Size: SH
  10. Push both sides of fitting together to cause the retaining tabs/fingers to snap into place.

  11. Object Number: 12787  Size: SH
  12. Pull on both sides of fitting to make sure connection is secure once installed.

  13. Object Number: 20434  Size: SH
  14. Install the fuel pressure regulator and crankcase ventilation vacuum lines.

  15. Object Number: 20450  Size: SH
  16. Install the fuel rail ground wire (1) at rear cylinder head.
  17. Install the injector harness and injector electrical connectors.
  18. Install the MAP sensor electrical connector.
  19. Install the front bank spark plug wires.
  20. Install the brake booster vacuum hose at intake manifold vacuum fitting.

  21. Object Number: 53639  Size: SH
  22. Install the EGR pipe at throttle body spacer.
  23. Tighten
    Tighten the EGR pipe bolt to 28 N·m (21 lb ft).


    Object Number: 41528  Size: SH
  24. Install the intake air duct clamp to the MAF Sensor.
  25. Install the intake air duct clamp to from the air cleaner assembly.
  26. Tighten fuel filler cap.
  27. Install the negative battery cable.
  28. Inspect for leaks.
  29. 19.1. Turn the ignition switch ON for 2 seconds.
    19.2. Turn the ignition switch OFF for 10 seconds.
    19.3. Turn the ignition switch ON.
    19.4. Check for fuel leaks.

    Object Number: 20426  Size: SH
  30. Install the intake manifold top cover.
  31. Tighten
    Tighten the nuts to 2 N·m (18 lb in).