GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Disconnect the negative battery cables. Refer to

    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.

    in General Information.
  2. Remove the intake manifold. Refer to Intake Manifold Removal.
  3. Disconnect the injection lines. Go to Fuel Injection Line Replacement .
  4. Disconnect the fuel inlet line from the injection pump.
  5. Disconnect all of the necessary harness connectors and the hoses from the injection pump.
  6. Disconnect the fuel return line at the top of the injection pump.
  7. Disconnect the oil fill tube.
  8. Remove the grommet from the oil filler tube.

  9. Object Number: 27614  Size: SH

    Important : Never engage the starter motor in order to rotate the engine when the injection pump is removed as severe engine damage will occur. With the injection pump removed, the pump driven gear could jam in the front housing by engaging the starter motor, resulting in a sheared crankshaft or camshaft gear key and possible valve train damage. Always bar the engine over by hand in order to avoid internal engine damage.

  10. Rotate the engine in order to gain access to the bolts (1) that hold the driven gear to the injection pump. The access is gained through the oil filler neck hole.
  11. Remove the driven gear bolts.
  12. Remove the injection pump flange nuts. Use wrench J 41069.
  13. Remove the injection pump.
  14. Cap all of the open lines and nozzles.
  15. Remove the flange gasket.

Installation Procedure

  1. Install the new flange gasket on the injection pump.

  2. Object Number: 27612  Size: SH

    Important: Be sure that the locating stud (1) on the injection pump hub goes into the slotted/elongated hole in the driven gear.

  3. Adjust the locating stud (1) to the proper position in order to match with the slotted/elongated hole in the driven gear.

  4. Object Number: 27613  Size: SH
  5. Install the injection pump, making sure the locating stud is positioned within the slotted/elongated hole (3) in the driven gear.
  6. Install the injection pump flange nuts.
  7. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).

    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.


    Object Number: 27614  Size: SH

    Important: None of the driven gear bolts should be torqued until all of the bolts are installed. This will allow for proper alignment of all of the bolt holes.

  8. Install the driven gear bolts (1).
  9. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).

  10. Install the grommet for the oil filler tube.
  11. Connect the oil filler tube.
  12. Connect the fuel feed line at the injection pump.
  13. Connect the fuel return line to the top of the injection pump.
  14. Connect all of the necessary harnesses and connectors.
  15. Connect the injection lines. Refer to the tags on the lines. Go to Fuel Injection Line Replacement .
  16. Install the intake manifold. Refer to Intake Manifold Installation.
  17. Connect the negative battery cables.
  18. Adjust the injection timing. Go to Checking/Adjust Injection Timing .