GM Service Manual Online
For 1990-2009 cars only

Tools Required

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

    Caution: Refer to Gasoline/Gasoline Vapors Caution in the Preface section.

    Caution: Remove the fuel tank cap and relieve the fuel system pressure before servicing the fuel system in order to reduce the risk of personal injury. After you relieve the fuel system pressure, a small amount of fuel may be released when servicing the fuel lines, the fuel injection pump, or the connections. In order to reduce the risk of personal injury, cover the fuel system components with a shop towel before disconnection. This will catch any fuel that may leak out. Place the towel in an approved container when the disconnection is complete.

  1. Turn the ignition OFF.
  2. Disconnect the battery negative cable in order to avoid possible fuel discharge if an accidental attempt is made to start the engine. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Loosen the fuel filler cap to relieve the fuel tank vapor pressure.
  4. 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

  5. Remove the cap on the fuel pressure service connection.
  6. 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.


    Object Number: 852270  Size: SH
  7. Connect the J 34730-1A  (1) and the J 42242  (2) to the fuel pressure service connection. Wrap a shop towel around the fitting while connecting the gauge to avoid spillage.
  8. 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.

  9. Place the bleed hose of the J 34730-1A  (1) into an approved gasoline container.
  10. Open the bleed valve on the J 34730-1A  (1) in order to bleed the fuel system pressure. The fuel connections are now safe for servicing.
  11. Place a shop towel under the fuel pressure service connection to catch any remaining fuel spillage.
  12. Remove both the J 34730-1A  (1) and the J 42242  (2) from the fuel pressure service connection.
  13. Drain any fuel remaining in the J 34730-1A  (1) into an approved gasoline container.
  14. Install the cap on the fuel pressure service connection.