Fuel Pressure: Notes

Basic diagnosis of fuel system should begin with determining fuel system pressure.

WARNING: ALWAYS relieve fuel pressure before disconnecting any fuel injection-related component. See appropriate RELIEVING FUEL PRESSURE procedure. DO NOT allow fuel to contact engine or electrical components.

Relieving Fuel Pressure (Vehicles With Fuel Rail Test Port) -Disconnect negative battery cable. Slowly open fuel tank cap to release pressure in tank. To release remaining pressure in system, remove fuel rail pressure test port cap. Place open end of Fuel Pressure Release Hose (C-4799-A) in approved gasoline container. Connect other end of pressure release hose to test port. Fuel pressure will bleed-off into container.

Relieving Fuel Pressure (Vehicles Without Fuel Rail Test Port) -Disconnect fuel pump wiring harness connector at fuel tank. Start engine. Let engine run until fuel is exhausted and engine stops. Turn ignition off. Disconnect negative battery cable. Connect fuel pump wiring harness connector.

WARNING: Perform fuel pump test with fuel tank at least half full. Before disconnecting fuel lines or fuel system components, relieve fuel pressure. See appropriate RELIEVING FUEL PRESSURE procedure.