Fuel Pressure Measurement

Special Tools 

EN 34730-91  Pressure Tester

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) and Special Tools (Removal and Installation)

1. Remove the protective cap from the test connection.
   Fig 1: View Of Fuel Pressure Tester

   Courtesy of GENERAL MOTORS COMPANY
   WARNING: 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.
   WARNING: 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.
2. Attach the EN 34730-91  tester (1) to the test connection.
3. Start the engine.
   • Bleed the pressure tester at idling speed.
   • Collect the exiting fuel in a suitable container.
   • Read the fuel pressure from the pressure gauge.
4. Detach the pressure gauge EN 34730-91  tester from the test connection.
   CAUTION:

   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