GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 34730-1A Fuel Pressure Gage

Installation Procedure

Caution: Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby.


    Object Number: 665445  Size: SH
  1. Remove the fuel injector sight shield (2).

  2. Object Number: 180378  Size: SH

    Caution: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete.

    Notice: Clean all of the following areas before performing any disconnections in order to avoid possible contamination in the system:

       • The fuel pipe connections
       • The hose connections
       • The areas surrounding the connections

  3. Install the J 34730-1A to the fuel pressure service connection, located on the fuel rail.
  4. Turn ON the ignition.
  5. Caution: Do not drain the fuel into an open container. Never store the fuel in an open container due to the possibility of a fire or an explosion.

  6. Place the bleed hose of the fuel pressure gage into an approved gasoline container.
  7. Open the bleed valve on the fuel pressure gage in order to bleed the air from the fuel pressure gage.
  8. Command the fuel pump ON with a scan tool.
  9. Close the bleed valve on the fuel pressure gage.
  10. Inspect for fuel leaks.

Removal Procedure

  1. Place the fuel pressure gage bleed hose into an approved container and open the bleed valve to bleed OFF fuel system pressure.
  2. Place a shop towel under the fuel pressure gage to catch any remaining fuel spillage.

  3. Object Number: 180378  Size: SH
  4. Remove the J 34730-1A from the fuel pressure connection.
  5. Drain any fuel remaining in the fuel pressure gage into an approved container.
  6. Inspect for leaks using the following procedure:
  7. 5.1. Turn ON the ignition, with the engine OFF for 2 seconds.
    5.2. Turn OFF the ignition for 10 seconds.
    5.3. Turn ON the ignition, with the engine OFF.
    5.4. Inspect for fuel leaks.
  8. Install the cap on the fuel pressure connection.

  9. Object Number: 665445  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.

  10. Install the engine sight shield.
  11. Tighten
    Tighten the engine sight shield bolt to 10 N·m (89 lb in).