GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2004 🢒 Rainier 🢒 Engine 🢒 Engine Controls - 4.8L, 5.3L, and 6.0L 🢒 Fuel Injection Fuel Rail Assembly Replacement

Removal Procedure
  1. Remove the air cleaner outlet duct. Refer to Air Cleaner Resonator Outlet Duct Replacement .

    2. Important:  An eight-digit identification number (1) is located on the fuel rail. Refer to this model identification number if servicing or part replacement is required.


    Object Number: 380659 Size: SH
  2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .

    3. Object Number: 898468 Size: SH
  3. Disconnect the air conditioning (A/C) compressor pressure switch electrical connector (2).
  4. Remove the wire harness from the clip (1) on the cylinder head.

    5. Object Number: 1204792 Size: SH
  5. Disconnect the mass air flow (MAF)/intake air temperature(IAT) sensor electrical connector (1).

    6. Object Number: 898329 Size: SH
  6. Disconnect the generator electrical connector.

    7. Object Number: 898331 Size: SH
  7. Disconnect the following electrical connectors on the right hand side of the engine:
    8. • Coil main electrical harness (1)
    • Electronic throttle control (ETC) (2)
    • Fuel injectors (3)

    Object Number: 1209783 Size: SH
  8. Perform the following steps in order to disconnect the fuel injector electrical connectors.
    9. 8.1. Mark the connectors to their corresponding injectors to ensure correct reassembly.
    8.2. Pull the connector position assurance (CPA) retainer (2) on the connector up 1 click.
    8.3. Push the tab (1) on the connector in.
    8.4. Disconnect the fuel injector electrical connector.
    8.5. Repeat the steps for each injector electrical connector.
  9. Remove the electrical harness from the clips on ignition coil bracket.

    10. Object Number: 898326 Size: SH
  10. Disconnect the following electrical connectors on the left hand side of the engine:
    11. • Evaporative emission (EVAP) purge solenoid (1)
    • Knock sensor (2)
    • Manifold absolute pressure (MAP) sensor (3)
    • Main coil (5)
    • Fuel injectors (4).
  11. Remove the electrical harness from the clips on ignition coil bracket.

    12. Object Number: 647793 Size: SH
  12. Remove the positive crankcase ventilation (PCV) hose (with valve).

    13. Object Number: 899740 Size: SH
  13. Remove the upper engine wire harness retainer nut (1).
  14. Reposition the upper engine wire harness aside.

    15. Object Number: 856643 Size: SH
  15. Disconnect the fuel feed and return pipes (1) from the fuel rail. Refer to Metal Collar Quick Connect Fitting Service .
  16. Disconnect the fuel pressure regulator vacuum line.

    17. Object Number: 376389 Size: MH
  17. Remove the fuel rail bolts.

    18. 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.

    Important: Before removal, clean the fuel rail with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak the fuel rail in liquid cleaning solvent.

  18. Remove the fuel rail.

    19. Object Number: 351185 Size: SH
  19. Remove the fuel injector lower O-ring seal (4) from each injector, if necessary.
  20. Discard the O-ring seals.

Installation Procedure

    Object Number: 351185 Size: SH
  1. Lubricate the NEW lower injector O-ring seals (4) with clean engine oil.
  2. Install the NEW O-ring seals (4) onto each injector, if necessary.

    3. Object Number: 376389 Size: MH
  3. Install the fuel rail.

    4. Notice: Refer to Fastener Notice in the Preface section.

  4. Apply a 5 mm (0.020 in) band of threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent, to the threads of the fuel rail bolts.
  5. Install the fuel rail bolts.

    6. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 856643 Size: SH
  6. Connect the fuel pressure regulator vacuum line.
  7. Connect the fuel feed and return pipes (1) to the fuel rail. Refer to Metal Collar Quick Connect Fitting Service .

    8. Object Number: 899740 Size: SH
  8. Position the upper engine wire harness over the engine.
  9. Install the upper engine wire harness retainer nut (1).

    10. Tighten
    Tighten the nut to 5 N·m (44 lb in).


    Object Number: 647793 Size: SH
  10. Install the PCV hose (with valve).

    11. Object Number: 898326 Size: SH
  11. Connect the following electrical connectors on the left hand side of the engine:
    12. • EVAP purge solenoid (1)
    • Knock sensor (2)
    • MAP sensor (3)
    • Main coil (5)
    • Fuel injectors (4)

    Object Number: 1209783 Size: SH
  12. Perform the following steps in order to Connect the fuel injector electrical connectors.
    13. 12.1. Install the connectors to their corresponding injectors to ensure correct reassembly.
    12.2. Connect the fuel injector electrical connector.
    12.3. Push the CPA retainer (2) on the connector in 1 click.
    12.4. Repeat the steps for each injector electrical connector.
  13. Install the electrical harness to the clips on ignition coil bracket.

    14. Object Number: 898331 Size: SH
  14. Connect the following electrical connectors on the right hand side of the engine:
    15. • Coil main electrical harness (1)
    • ETC (2)
    • Fuel injectors (3)
  15. Install the electrical harness to the clips on ignition coil bracket.

    16. Object Number: 898329 Size: SH
  16. Connect the generator electrical connector.

    17. Object Number: 1204792 Size: SH
  17. Connect the MAF/IAT sensor electrical connector (1).

    18. Object Number: 898468 Size: SH
  18. Install the wire harness to the clip (1) on the cylinder head.
  19. Connect the A/C compressor pressure switch electrical connector (2).
  20. Install the air cleaner outlet duct. Refer to Air Cleaner Resonator Outlet Duct Replacement
  21. Install the fuel fill cap.
  22. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  23. Use the following procedure in order to inspect for leaks:
    24. 23.1. Turn the ignition ON, with the engine OFF, for 2 seconds.
    23.2. Turn the ignition OFF for 10 seconds.
    23.3. Turn the ignition ON, with the engine OFF.
    23.4. Inspect for fuel leaks.