High idle problems.
First off, I have a 1995 Mercury Cougar 3.8L. It has been fully tuned up, plugs, wires, air and fuel filter, cap, rotor.
When I start it from cold the rpm shoots up to about 3000 for about 5 sec. Then slowly goes back down to idle, 650 to 700 then starts to miss. Accelerates and cruises down the road just fine, no miss. Only at an idle, warm or cold.
Now if I'm driving down the road, rpm's at about 2700 and I let off the gas it keeps going, putting it together in neutral and the rpm's spike to about 5000. I replaced the air idle control valve hoping that's it but there was no change. I'm afraid if it keeps starting like that I'm going to mess up my valves. I can already hear them click when starting but that goes away when the idle drops.
Last edited by Rodeo Joe; 11-24-2015 at 03:33 PM.