Rough Running at All Engine Speeds
FAULT INDICATIONSUneven power output from all cylinders.
FAULT TRACING CONDITIONS
Before fault tracing, ensure that:
^ No diagnostic trouble codes are present,
^ The engine is at operating temperature, and
^ All fuses are clean and intact.
POSSIBLE FAULT CAUSE
^ Air leaks at the induction system
^ Air leaks at the crankcase
^ Fuel filter restricted
^ Poor fuel quality or contaminated
^ Fuel supply lines damaged or misrouted
^ Fuel pump defective (insufficient output)
^ Fuel pressure regulator defective
Testing and Inspection
^ Carbon on intake valves
^ Fuel injectors defective or clogged
^ DME control unit defective, Computers and Control Systems