2 - Fuel System Pressure Test

This test will determine whether there is adequate fuel pressure delivered to the fuel injectors to start and run the engine under low load conditions.

CAUTION:
^ DO NOT ALLOW SMOKING OR THE USE OF OPEN FLAMES IN THE AREA WHERE WORK ON THE FUEL OR EVAP SYSTEM IS TAKING PLACE. ANYTIME WORK IS BEING DONE ON THE FUEL SYSTEM, DISCONNECT THE NEGATIVE BATTERY CABLE, EXCEPT FOR THOSE TESTS WHERE BATTERY VOLTAGE IS REQUIRED.

^ WHENEVER FUEL LINE FITTINGS ARE LOOSENED OR REMOVED, WRAP A SHOP CLOTH AROUND THE FITTING AND HAVE AN APPROVED CONTAINER AVAILABLE TO COLLECT ANY FUEL.




1. Relieve fuel system pressure. (Refer to "Fuel System Pressure Relief".) Service and Repair
2. Connect fuel gauge pressure adapter (309725) and pressure gauge to fuel pressure test port.

IMPORTANT: Battery must be at a minimum of 12 volts when performing any fuel system test. Charge battery before proceeding if below 12 volts.




3. Using Scan Tool, energize the fuel pump for a minimum of 10 seconds.
3.1 Record the fuel pressure.
3.2 Repeat this procedure a minimum of two times.
4. While fuel pump is energized remove fuel pressure regulator vacuum line and inspect both ends for liquid fuel.
^ If liquid fuel is present replace fuel pressure regulator before proceeding. (Refer to "Fuel Pressure Regulator Removal" procedure.)
^ If no liquid is present proceed to step 5.
5. Compare the pressure recorded to the published specification.
6. Return to "Fuel System Diagnostic Chart" and use test result to make appropriate decision.