Idle surge HELP!!

OK here it is I have an 82 capri (yea I know its not really a mustang but the fender flares look cool) with a 302 sefi and aod out of an 88 tbird in it. It has a real bad idle surge . I have replaced the tab the egr and sensor and the ics no luck. I feel like I am throwing money in the gas tank for no good reason. If I disconect the egr vacum line the idle jumps up to 2000 but smooths out. If I disconect the tab connector it smooths out but I have to hold the throttle part way open or it stalls. Help I am running outa money to throw at