1992 Eagle Talon Engine Idle

Hey, my car idle surges. I replaced the ISC, blocked off the EGR Valve, replaced the ECU. None of that stopped it. I just recently messed with the idle sensor? (It's the little thing that screws into the throttle and a wire plugs in the top of it). I got it to where it was a steady idle, but high. Then I tightened the BISS screw all the way and that put the idle about where it should be. I then realized, it's only idling correctly when it's warm, when it's cold, it surges and/or idles high. I was told that my intake manifold could be leaking, and to spray carb cleaner around it to see if it is. Could that be the problem, even though it's not a constant thing? Would spraying carb cleaner around the manifold hurt my engine at all? Thanks for the help in advance. Gary