Hi, my 88 mustang gt kinda rev's up on it's own and then drop's back down.. Especially when you first start it up... it rev's up quickly then kinda calms down. But it's really uneasy... Any idea's????
how modded is your car?A friend of mine had this problem after he put in a crate engine. Is yours auto or stick. We pulled that motor later and put in a stick and the problem went away. They make a part that goes inbetween your IAC and the throttle body. It has two adjutments on it that helps this problem. If that is indeed your problem.
I have underdrive pulleys, electric fan, new alt.. a/c was eliminated.. and shorty equal length headers... other than that.. nothing has been changed from stock....