Gasoline Engines

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

1) Fuel System Visual Inspection
Visually inspect fuel system, including fuel lines, connections, injectors and electrical connections. Ensure Inertia Fuel Shutoff (IFS) switch is not tripped. Check condition of battery and fuses. Ensure fuel level in tank is sufficient.

2) Check Fuel Pressure

Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Release fuel system pressure. See FUEL PRESSURE RELEASE . Install fuel pressure gauge. Using scan tool, access OUTPUT TEST MODE. For additional information, see OUTPUT TEST MODE under ADDITIONAL SYSTEM FUNCTIONS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article. Command fuel pump ON and run fuel pump to obtain maximum fuel pressure. Record fuel pressure. Compare measured fuel pressure to fuel pressure specification. See FUEL PRESSURE SPECIFICATIONS . If fuel pressure is within specification, go to next step. If fuel system pressure is not within specification, go to TEST HC, step 1) under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article for fuel delivery system diagnosis.

3) Check Fuel Pressure Leakdown

With fuel pressure gauge still installed, cycle ignition switch on and off several times. Record fuel pressure. After one minute with ignition off, fuel pressure should remain within 5 psi (34 kPa) of maximum fuel pressure. If fuel pressure remains within specification, system is capable of maintaining fuel pressure. If fuel pressure does not remain within specification, check for leaking fuel injectors or fuel pressure regulator.