Always begin diagnosis of the electronic fuel injection system with the On-Board Diagnostic (OBD) System Check before proceeding to any other diagnostics. This will reduce diagnosis time and prevent 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. Diagnosis of electronic fuel injection pump, including the fuel injection solenoid, fuel solenoid driver, injection timing stepper motor and 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.