GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 34730-1A Fuel Pressure Gage

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.


    Object Number: 180378  Size: SH
  1. Turn the ignition OFF.
  2. 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.

  3. Disconnect the negative battery cable in order to avoid possible fuel discharge if an accidental attempt is made to start the engine.
  4. Loosen the fuel filler cap in order to relieve the fuel tank vapor pressure.
  5. Remove the engine cover. Refer to Engine Cover Replacement .
  6. Connect the J 34730-1A or the equivalent to the fuel pressure connection.
  7. Wrap a shop towel around the fitting while connecting the gage in order to avoid spillage.
  8. Install the bleed hose of the gage into an approved container.
  9. Open the valve on the gage in order to bleed the system pressure. The fuel connections are now safe for servicing.
  10. Drain any fuel remaining in the gage into an approved container.
  11. Install the engine cover. Refer to Engine Cover Replacement .