Hi guys got a quick question. When the car is cold, and you blip the gas pedal, the rpms on the car go up and down pretty quick, it feels real snappy and tight. But when the motor gets to operating temperature, and you do the same thing, blip the gas, the rpms climb the same, but drop slow for some reason, what would cause this? Im talking about basically revving the car in park or neutral.

 

Does anybody have an answer or is the question not understood?

 

When I owned a 5.0 GT if my timing was advanced the rpms would decrease slower than when I had timing a little retarded. I don't know if that helps at all.

 

Did it not happen before the tune? the throttle follower IAC counts may be been altered in the tune, or a vacuum leak.

 

How many miles on the motor?