GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 XLR 🢒 Engine 🢒 Engine Controls - 4.6L (LH2) 🢒 Fuel Injection Fuel Rail Assembly Replacement

Removal Procedure

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: 931736 Size: SH
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  2. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
  3. Relieve the fuel system pressure. Refer to the Fuel Pressure Relief .
  4. Clean the fuel rail assembly 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.
  5. Disconnect the fuel feed and return pipes  (2, 3) from the fuel rail. Refer to Metal Collar Quick Connect Fitting Service .
  6. Disconnect the positive crankcase ventilation (PCV) air tube from the cam cover.

    7. Object Number: 490817 Size: SH
  7. Disconnect the fuel injector electrical connectors (1) from each fuel injector (2).

    8. Object Number: 927871 Size: SH
  8. Remove the engine wiring harness from the fuel rail stud.

    9. Object Number: 927838 Size: SH
  9. Remove the engine wiring harness from the clips.
  10. Lay the harness aside.

    11. Object Number: 928165 Size: SH
  11. Remove the fuel rail attaching studs.
  12. Remove the fuel rail .
  13. Remove the injector lower O-ring seal from the spray tip end of each injector.
  14. Discard the O-ring seals.
  15. If replacing the fuel rail, remove the fuel injectors. Refer to Fuel Injector Replacement .

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: 928165 Size: SH
  1. Lubricate the new lower injector O-ring seals with clean engine oil.
  2. If replacing the fuel rail, install the fuel injectors. Refer to Fuel Injector Replacement .
  3. Install the new O-ring seals on the spray tip end of each injector.
  4. Install the fuel rail .

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

  5. Install the fuel rail attaching studs  (2).

    6. Tighten
    Tighten the studs to 9 N·m (80 lb in).


    Object Number: 927838 Size: SH
  6. Position the harness to the engine.
  7. Install the engine wiring harness to the clips.

    8. Object Number: 927871 Size: SH
  8. Install the engine wiring harness to the fuel rail stud.

    9. Object Number: 490817 Size: SH
  9. Connect the fuel injector electrical connectors (1) to each fuel injector (2).

    10. Object Number: 931736 Size: SH
  10. Connect the fuel feed and return pipes (2, 3) to the fuel rail. Refer to Metal Collar Quick Connect Fitting Service .
  11. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  12. Inspect for fuel leaks using the following procedures:
    13. 12.1. Turn ON the ignition, with the engine OFF for 2 seconds.
    12.2. Turn OFF the ignition for 10 seconds.
    12.3. Turn ON the ignition, with the engine OFF.
    12.4. Inspect for fuel leaks.
  13. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .