Diagnostic Aids

When PCM is in back-up fuel, long crank times, fast idle and poor performance conditions will exist. Check for poor connections at crankshaft position sensor and PCM. Intermittents could be caused by poor connections or wiring. When diagnosing intermittents, reproduce conditions under which failure occurs. Operate engine at a higher temperature and near RPM when problem occurs. Since heat and vibration often cause intermittents, operating engine at a higher temperature and near RPM when problem occurs could cause intermittent condition.