My 2003 Ford Fairmont engine stumbles and hesitates when the air conditioning is running. It is worse using standard unleaded and reduces on high octane unleaded. Is this electrical or fuel line related? The car is designed for standard unleaded. It also hesitates and stumbles when accelerating briskly. Under light throttle this does not occur.
Sunday, February 20th, 2011 AT 9:29 AM