GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2007 🢒 Isuzu - N Series 🢒 Engine 🢒 Engine Controls and Fuel - 4.8L, 5.3L, and 6.0L 🢒 Fuel Injection Fuel Rail Assembly Replacement

Removal Procedure

    Object Number: 310125 Size: SH
  1. Remove the upper engine wire harness retainer nut.
  2. Disconnect the evaporative emission (EVAP) purge solenoid electrical connector.
  3. Reposition the upper engine wire harness aside.
  4. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .

    5. Object Number: 820976 Size: SH
  5. Mark the electrical connectors to their corresponding injectors to ensure correct sequential injector firing order after reassembly.

    6. Important: When disconnecting the Multec® 2 fuel injector connectors, DO NOT use pliers or other hand tools, as the connector ends may become mangled and be rendered unusable.

  6. Pull the connector position assurance (CPA) (2) on the injector connector up.
  7. Push the tab (1) on the injector connector in.

    8. Object Number: 820977 Size: SH
  8. While pushing the tab (1) on the injector connector in, release the CPA (2).
  9. Disconnect the fuel injector connector electrical connector.
  10. Repeat the steps for each injector connector.

    11. Object Number: 300360 Size: SH

    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.

  11. Disconnect the fuel feed and return pipes (1, 2) from the fuel rail.
  12. Disconnect the fuel pressure regulator vacuum line.

    13. Object Number: 350543 Size: SH
  13. Loosen the retaining clip attaching screw (22) at the right hand fuel rail.

    14. Object Number: 260176 Size: SH
  14. Remove the fuel rail bolts.
  15. Remove the fuel rail.

    16. Object Number: 351185 Size: SH
  16. Remove and discard the fuel injector lower O-ring seals (4) from the injectors (3).

Installation Procedure

    Object Number: 351185 Size: SH
  1. Lubricate the NEW fuel injector lower O-ring seals (4) with clean engine oil.
  2. Install the NEW O-ring seals (4) to the end of each fuel injector (3).

    3. Object Number: 350543 Size: SH
  3. Remove the retaining clip attaching screw (22) and crossover pipe retainer (21) to the right hand fuel rail.
  4. Remove the crossover pipe rail  (25) from the right fuel rail (15).
  5. Remove the crossover pipe O-ring (20).
  6. Lubricate a NEW O-ring (20) with clean engine oil.
  7. Install a NEW crossover pipe O-ring (20) on the crossover pipe (25) .
  8. Install the crossover pipe (25) into the right fuel rail (15).

    9. Important: When installing the retaining clip attaching screw for the crossover pipe, always start the screw by hand. This will prevent consequent stripping of the threads in the fuel rail.

  9. Loosely install the crossover pipe retainer (21) and retaining clip attaching screw (22) to the right hand fuel rail.

    10. Object Number: 260176 Size: SH
  10. Install the fuel rail.

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

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

    13. Tighten

    1. Tighten the bolts to 10 N·m (89 lb in).
    2. Tighten the screw to 3.8 N·m (34 lb in).

    Object Number: 300360 Size: SH
  13. Connect the fuel pressure regulator vacuum line.
  14. Connect the fuel feed and return pipes (1, 2) to the fuel rail.
  15. Connect the fuel injector electrical connectors.
    16. • Install each electrical connector onto the correct fuel injector in order to ensure correct sequential injector firing order.
    • Rotate the fuel injectors as required in order to avoid stretching the wire harness.

    Object Number: 310125 Size: SH
  16. Position the upper engine wire harness in place.
  17. Connect the EVAP purge solenoid electrical connector.
  18. Install the retainer nut to the upper engine wire harness.

    19. Tighten
    Tighten the nut to 5.5 N·m (49 lb in).

  19. Use the following procedure in order to inspect for leaks:
    20. 19.1. Turn ON the ignition, with the engine OFF, for 2 seconds.
    19.2. Turn OFF the ignition for 10 seconds.
    19.3. Turn ON the ignition, with the engine OFF.
    19.4. Inspect for fuel leaks.