Always begin the diagnosis of the electronic fuel injection system with the On-Board Diagnostic (OBD) System Check before proceeding to any other diagnostics. This will reduce the diagnosis time and prevent an unnecessary replacement of parts. The On-Board Diagnostic (OBD) System Check will give direction to further diagnostics, such as Engine Cranks But Will Not Run or a DTC Table. The diagnosis of an electronic fuel injection pump, including the fuel injection solenoid, the fuel solenoid driver, the injection timing stepper motor and the engine shutoff solenoid also starts with the On-Board Diagnostic (OBD) System Check.

If a driveability symptom exists, refer to the particular symptom in the Driveability Symptoms.

Damage to the injection lines including chinking that causes restrictions or leakage could effect driveability or cause a DTC to set.

A fuel odor may be the result of a leaking fuel feed, return pipe or hose. Fuel pipes that are pinched, plugged, or misrouted may cause a restricted fuel delivery.