My GMC Safari van's has a rough idle, engine vibration, when in drive with the brake on. This condition get worse when the air conditioner is running. Once you place your foot on the gas to take off the engine runs smooth. It runs great in all other throttle positions. Before the condition, the van would get approximately 19mpg, now it get approx. 17mpg at best. I checked to see if any of the air lines were leaking, no leaks were found. There are no error codes displayed. Thus far, I have replaced plug, wires, engine idle solenoid, still same problem. Any ideas as to what this could be?
Sep 27, 2010 at 3:04 PM