help guys i own a 1993 d150 with a slight issue when i sit in park with the engine running the engine idles higher and lower again i was thinking that it might be the idle air control valve . But i have not had the chance to look in to it. Any ideas ? gonna try to clean the trottle body and idle air control valve in the morning. truck is a 3.9 with new plugs , new cap and rotor , i am kinda stumped at this point. thanks in advance .