I have a 90 Integra LS with 190k miles on it, I have an intake header and exhaust. Im not sure why i mentioned that i just thought it might help. When I start my car after its been sitting cold, it will have a very high idle then after it settles down to about 1k rpm, it will drop and almost cut off, then jump back up as if i hit the gas, then drop back down to almost 0 rpm , then jump back up to about 1 or 1.5k rpm, and over and over again until it heats up. Please someone tell me what this problem is?! I have a very loud exhaust and for that to happen is very embarrassing. Lol its hard to look cool with a LOUD busted car.