When i go out to my car in the morning it starts off at 2500rpm and then goes back and forth between 2500 and 2500 until the engine is completely warmed up. I don't get a check engine light, everything works just fine. It's just during the "warm up cycle" that it has a "jumping idle." The car runs great, nice and fast. The engine has 50K miles on it and it's out of a 94 Integra LS. It never has any probs with overheating or anything, and never shuts down. I changed the MAP sensor today, and still no good. This engine was a junkyard engine...do you think that might have anything to do with it? Also, would a vacuum leak cause it to have a jumping idle when the motor is cold? I hope this is a little more desciptive.