A buddy of mine has a 97 civic, and recently swapped the original auto tranny for a 99 civic auto tranny, and swapped in an engine out of a 95 civic.

He claims to have removed all of the electronics, sensors/distributor/throttle body/injectors, out of the original engine and to have installed them in the new one, however, he did not swap out computers, and is still using the one that originally came in his car. He also did not change the sensors on the tranny. I'm not sure if the tranny sensors would have any effect on engine idle or not? I know that there are select vehicles of which correct engine operation is in fact dependent on tranny sensors, but I just don't remember for sure if this is one of them.


Any thoughts on what may be causing this? It's not low on coolant.

Thanks much
Steve

 

I was hoping for a little bit more informative response than that

 

Vacuum Pump leak?