Rough idle when fueling.

For safety reasons, the engine should be turned off when refueling. If problem does not occur during normal uses, then it is nothing to worry about.

Under normal driving I have an engine stumble only when the a/c is on, other than that it runs fine. Yes I know the car should be off when fueling, and it usually is but once when I had someone in the car it was real hot and I left it running for the passenger, that's when I noticed the stumble.

Vehicle is equipped with emission controls and when fuel cap is off, the EVAP system would detect presence of fuel fuems which can cause it to react causing the erratic idling.

As to the engine stumble when A/C is turned on, if it occurs only at the time A/C compressor cuts in when turned on and/or when gas pedal is released after accelerating, the idle control system is not working efficiently.

Getting the throttle body and ISC cleaned should resolve the problem.

Thanks so much for your reply, you guys are great.

You're welcome.

Have a nice day.