95 lumina 3.4 surges when cold

alright so this problem has been a pain....on cold days the lumina starts up but surges irratically, sometimes even stalling, rpms jump from 500-3000 and takes atleast 5 mins to warm up and finally quit surging. Weve taken it to pepboys, they replaced the O2 sensor on one trip, the next trip they cleaned the throttle body, the next trip (after the transmission blew) they supposedly found a vacuum leak, but it still does it, and before i demand a refund on the labor they charged me i want some more ideas on what the problem could be.....just a review, surges when cold and once warm idles relativly smoothly, thanks in advance, any help would be greatly appriciated

sheck your idel

I'd check 3 things, EGR valve (not completely closing), IAC motor (pintle gummed up in bore of throttle body or malfunctioning) and lower intake gaskets (causing vacuum leak). All are fairly common problems, and all will creat a cold idle surge that will go away once the engine warms up.