Need some help here. I am having a problem with my 1995 avenger with the 2.0 and auto trans. It will run fine for 10-15 min and drive 6-8 miles working great. Than all of a sudden the engine will start surging between 1200 and 2500 rpm.

So far I have replaced the coil, plugs, wires, fuel pump, new battery terminals and checked voltages (good) and replaced the IAC and throttle body. Checked the EGR to make sure the valve is working. The crank shaft position sensor has also been replaced. Can not find any vacuum leaks. The car is warm way before this problem starts.

I am at a loss right now of whats going on and why it is acting like this. Any help or suggestions you can give me would be appreciated.

Thank you!

 

Just hooked it up to a code reader. Getting a P0351 code when it starts to surge and rev. Cleared out the code and restarted the engine. Still surging but the code did not come back yet.

 

P0351 is Primary ignition since you say the coils been replaced it might have been defective or the code was leftover

With it seeming to happen when warm I'll bet the cause is electronic/electrical might be computer or the CPS that you said you replaced