GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Aurora 🢒 Engine 🢒 Engine Controls - 4.0L and 4.6L 🢒 Fuel Injection Fuel Rail Assembly Replacement

Removal Procedure

Tools Required
    • J 34730-1A Fuel Pressure Gauge
    • J 37088-A Fuel Line Quick-Connect Tools
    • J 41081 Injector Remover

    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.

  1. Relieve fuel system pressure. Refer to the Fuel Pressure Relief .

    2. Object Number: 41531 Size: SH
  2. Remove the air intake duct.

    3. Object Number: 53639 Size: SH
  3. Remove the EGR pipe at throttle body spacer.
  4. Remove the brake booster vacuum hose at intake manifold vacuum fitting.
  5. Remove the front bank spark plug wires. Refer to Spark Plug Wire Harness Replacement .

    6. Object Number: 198349 Size: SH
  6. Remove the MAP sensor electrical connector (1) from the MAF sensor (2).

    7. Object Number: 18886 Size: SH
  7. Remove the fuel injector electrical connectors from the fuel injectors.

    8. Object Number: 198301 Size: SH
  8. Lay the harness aside.
  9. Remove the fuel rail ground wire (7) bolt at the rear cylinder head.
  10. Remove the fuel pressure regulator (1) from the fuel rail. Refer to the Fuel Pressure Regulator Replacement .

    11. Object Number: 43066 Size: SH
  11. Remove the crankcase ventilation vacuum lines.

    12. Object Number: 198301 Size: SH
  12. Remove the quick-connect fittings (2) at the fuel rail. Refer to Metal Collar Quick Connect Fitting Service .
  13. Remove the fuel rail end-point bracket retainer bolt.

    14. Object Number: 19023 Size: SH
  14. Remove the throttle body mount bolts.
  15. Remove the throttle body. Refer to Throttle Body Assembly Replacement .
  16. Remove the throttle body spacer (3).
  17. Remove the intake manifold to throttle body spacer O-ring seal.

    18. Object Number: 198301 Size: SH
  18. Release the locking tabs (8) on fuel rail by pushing toward center of intake manifold and pry each injector out of intake manifold using J 41081.

    19. Object Number: 18881 Size: SH
  19. Lift the fuel rail and move the fuel rail toward the left hand side of the vehicle until the fuel pipes clear the intake plenum.
  20. An eight digit identification number is stamped on the fuel rail assembly. The model identification number contains the Julian Date, the year, and the shift. Refer to this model identification number if servicing or part replacement is required.

Disassembly Procedure

    Object Number: 18881 Size: SH
  1. Remove the fuel injector harness.

    2. Object Number: 18873 Size: SH
  2. Remove the clips (3) from the injectors (5) on the fuel rail.

    3. Object Number: 168577 Size: SH
  3. Remove the upper (3) and lower (2) seals from the injector(s) (1).
  4. Discard the seals after removal.

Assemble Procedure

    Object Number: 198301 Size: SH
  1. Lubricate the upper (6) and lower (4) injector O-rings with clean oil and install the O-rings on to the fuel injectors.

    2. Object Number: 18881 Size: SH
  2. Assemble the injectors to the fuel rail with new retainer clips.
  3. Assemble the injector harness.

Installation Procedure

    Object Number: 18881 Size: SH
  1. Install the fuel rail with injectors to intake manifold.
  2. The fuel injectors are fully seated when a snap is heard.

    3. Object Number: 19023 Size: SH

    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 new O-ring seal between the throttle body spacer (3) and intake manifold (4).
  4. Install throttle body spacer (3).

    5. Tighten
    Tighten the throttle body spacer bolts to 12 N·m (106 lb in).

  5. Install the new throttle body gasket (2) between the throttle body (1) and throttle body spacer (3).
  6. Install the throttle body (1). Refer to Throttle Body Assembly Replacement .

    7. 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.

  7. Install the throttle body mount bolts.

    8. Tighten
    Tighten the throttle body mount bolts to 12 N·m (106 lb in).


    Object Number: 20434 Size: SH
  8. Install the fuel pressure regulator if the fuel pressure regulator was removed from the fuel rail. Refer to Fuel Pressure Regulator Replacement .

    9. Object Number: 43066 Size: SH
  9. Install the crankcase ventilation vacuum lines.

    10. Object Number: 198301 Size: SH
  10. Install the fuel rail ground wire at rear cylinder head (7).

    11. Tighten
    Tighten the fuel rail ground wire bolt to 6 N·m (53 lb in).


    Object Number: 18881 Size: SH
  11. Install the fuel injector electrical connector(s).

    12. Object Number: 198349 Size: SH
  12. Install the MAP sensor electrical connector (1) to the MAF sensor (2).
  13. Install the front bank spark plug wires. Refer to Spark Plug Wire Harness Replacement .
  14. Install the brake booster vacuum hose at intake manifold vacuum fitting.

    15. Object Number: 53639 Size: SH
  15. Install the EGR pipe at throttle body spacer.

    16. Tighten
    Tighten the EGR pipe bolt to 24 N·m (18 lb in).


    Object Number: 175094 Size: SH
  16. Install the fuel rail end-point bracket (1) retainer bolt (2).

    17. Tighten
    Tighten the bolt to 11 N·m (97 lb in).


    Object Number: 41531 Size: SH
  17. Install the air intake duct.

    18. Tighten
    Tighten the clamp(s) to 3.5 N·m (31 lb in) at the MAF sensor and 1.8  N·m (16 lb in) at the air cleaner.


    Object Number: 153705 Size: SH
  18. Tighten fuel filler cap (1).
  19. Install the negative battery cable.
    20. 19.1. Turn ignition switch to the On position 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.
  20. Install the rear seat cushion. Refer to Rear Seat Cushion Replacement .

    21. Object Number: 42751 Size: SH
  21. Install the intake manifold top cover.

    22. Tighten
    Tighten the nuts to 3 N·m (27 lb in).