GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 34730-1A Fuel Pressure Gage
    • J 42242 Fuel Pressure Gage Adapter

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.

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


    Object Number: 1652887  Size: SH
  1. Remove the engine sight shield. Refer to Intake Manifold Sight Shield Replacement .
  2. Remove the cap from the fuel pressure test port valve.

  3. Object Number: 1652917  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.

  4. Connect the J 42242  (1) to the fuel pressure test port valve. Wrap a shop towel around the fitting while connecting the adapter in order to avoid spillage.
  5. Connect the J 34730-1A  (2) to the J 42242  (1). Wrap a shop towel around the fittings while connecting the gage to the adapter in order to avoid spillage.
  6. Turn ON the ignition, 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 fuel pressure gage into an approved gasoline container.
  9. Open the bleed valve on the fuel pressure gage 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 fuel pressure gage.
  12. Command the fuel pump ON with a scan tool.
  13. Inspect for fuel leaks.

Removal Procedure


    Object Number: 1652917  Size: SH
  1. Drain any fuel remaining in the gage into an approved container.
  2. Place a shop towel under the J 34730-1A  (2) and the J 42242  (1) to catch any remaining fuel spillage.
  3. Remove the J 34730-1A  (2) and the J 42242  (1).
  4. Inspect for leaks using the following procedure:
  5. 4.1. Turn ON the ignition, with the engine OFF for 2 seconds.
    4.2. Turn OFF the ignition, for 10 seconds.
    4.3. Turn ON the ignition, with the engine OFF.
    4.4. Inspect for fuel leaks.
  6. Install the cap to the fuel pressure test port valve.
  7. Install the engine sight shield. Refer to Intake Manifold Sight Shield Replacement .