94 Mustang GT - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

daleisgood · 05-29-2006, 16:19

I have put a cold air induction, new headers, high flow oil pump, flow masters on my car.

Lately, after driving for awhile (with AC on especially) i have been getting this surge. It is like it tries to accelarate a couple hundred RPM then shifts back or or decelareates.

I have been told it could be O2 sensors or TPS.

Any help for me out here.

daleisgood@tds.net

redneckf150 · 05-29-2006, 18:57

Sounds like you're low on freon. Have your pressures checked at a shop...they'll usually do it for free...

daleisgood · 05-30-2006, 17:42

thanks for your help I will do that, but would this make the RPM surge.

redneckf150 · 05-30-2006, 18:06

I've read quite a few threads on this forum and others, where it is typical for an engine to surge when it is low on freon. My A/C compressor is currently cutting out when I gag it, or when I really slam on the brakes; kind of the opposite situation as yours, but it is also caused by the same system. The A/C systems now include low and high-pressure sensors, as well as microcontrolers which can also be the source of these problems (as is in my case). Good luck!