GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

An eight digit identification number is stamped on the left hand fuel rail (fueling even cylinders 2, 4, 6). Refer to this number if servicing or part replacement is required.

Caution: In order to reduce the risk of fire and personal injury that may result from a fuel leak, always install the fuel injector O-rings in the proper position. If the upper and lower O-rings are different colors (black and brown), be sure to install the black O-ring in the upper position and the brown O-ring in the lower position on the fuel injector. The O-rings are the same size but are made of different materials.

Notice: Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering the open pipes and passages.


    Object Number: 22505  Size: SH
  1. Relieve fuel system pressure. Refer to Fuel Pressure Relief .
  2. Remove the upper intake manifold. Refer to Upper Intake Manifold Replacement .
  3. Remove the engine compartment fuel pipe retainer bolt.
  4. Disconnect the engine fuel feed pipe at fuel rail.

  5. Object Number: 22507  Size: SH
  6. Disconnect the engine fuel return pipe at the fuel pressure regulator.
  7. Remove the fuel feed pipe and fuel return pipe O-rings and discard.
  8. Disconnect the main injector harness electrical connector.

  9. Object Number: 372749  Size: SH
  10. Pull up the lock release (2) of the fuel injector connector.

  11. Object Number: 372753  Size: SH
  12. Depress the lock tab (1) on the fuel injector connector.
  13. Remove the fuel injection harness from the fuel rail.

  14. Object Number: 15986  Size: SH
  15. Disconnect the coolant temperature sensor electrical connector.

  16. Object Number: 531027  Size: SH
  17. Remove the fuel rail retaining bolts.
  18. Remove the fuel rail assembly.
  19. Remove the injector O-ring seal from spray tip end of each injector. Discard seals.

Installation Procedure

Notice: 

   • Use care when servicing the fuel system components, especially the fuel injector electrical connectors, the fuel injector tips, and the injector O-rings. Plug the inlet and the outlet ports of the fuel rail in order to prevent contamination.
   • Do not use compressed air to clean the fuel rail assembly as this may damage the fuel rail components.
   • Do not immerse the fuel rail assembly in a solvent bath in order to prevent damage to the fuel rail assembly.


    Object Number: 531027  Size: SH
  1. Install the fuel rail assembly into the intake manifold. Tilt rail assembly to install injectors.
  2. 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 fuel rail attaching bolts.
  4. Tighten
    Tighten the fuel rail attaching bolts to 10 N·m (89 lb in).


    Object Number: 15986  Size: SH
  5. Connect the coolant temperature sensor electrical connector.

  6. Object Number: 372749  Size: SH
  7. Install the injector electrical harness to the fuel rail.
  8. Connect the injector electrical connectors.
  9. Push the slide lock (2) into the locked position.
  10. Connect the main injector harness electrical connector.

  11. Object Number: 22505  Size: SH
  12. Install the new O-rings on fuel feed pipe and fuel return pipe.
  13. Connect the fuel feed pipe at the fuel rail.
  14. Tighten
    Tighten the engine fuel feed pipe nut to 17 N·m (13  lb ft).


    Object Number: 22507  Size: SH
  15. Connect the fuel return pipe at the fuel pressure regulator.
  16. Tighten
    Tighten the engine fuel return pipe nut to 17 N·m (13 lb ft).

  17. Install the engine compartment fuel pipe retainer bolt.
  18. Tighten
    Tighten the fuel pipe retainer bolt to 25 N·m (18 lb ft).

  19. Install the upper intake manifold. Refer to Upper Intake Manifold Replacement .
  20. 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.

  21. Connect the negative battery cable.
  22. Inspect for fuel leaks using the following procedure:
  23. 14.1. Turn ON the ignition, for 2 seconds.
    14.2. Turn OFF the ignition, for 10 seconds.
    14.3. Turn ON the ignition.
    14.4. Inspect for fuel leaks.