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: 180378  Size: SH
  1. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical.
  2. 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. Remove the cap from the fuel pressure service connection.
  4. 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.

  5. Install the J 34730-1A to the fuel pressure service connection, located on the fuel rail. Wrap a shop towel around the fitting while connecting the J 34730-1A to avoid spillage.
  6. Turn the ignition ON, with the engine OFF.
  7. 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.

  8. Place the bleed hose of the J 34730-1A into an approved gasoline container.
  9. Open the bleed valve on the J 34730-1A in order to bleed the air from the fuel pressure gage.
  10. Command the fuel pump ON with a scan tool.
  11. Close the bleed valve on the J 34730-1A .
  12. Inspect for fuel leaks.

Removal Procedure

  1. Ensure the fuel pump is OFF

  2. Object Number: 180378  Size: SH
  3. Place the bleed hose of the J 34730-1A into an approved gasoline container.
  4. Open the bleed valve on the J 34730-1A in order to bleed the fuel system pressure.
  5. Place a shop towel under the fuel pressure service connection to catch any remaining fuel spillage.
  6. Remove both the J 34730-1A from the fuel pressure service connection.
  7. Drain any fuel remaining in the J 34730-1A into an approved gasoline container.
  8. Inspect for leaks using the following procedure:
  9. 7.1. Turn the ignition ON, with the engine OFF for 2 seconds.
    7.2. Turn the ignition OFF, for 10 seconds.
    7.3. Turn the ignition ON, with the engine OFF for 2 seconds.
    7.4. Turn the ignition OFF.
    7.5. Inspect for leaks.
  10. Install the cap on the fuel pressure service connection.
  11. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement in Engine Mechanical.