When the a/c is off, idle and performance seem ok, with a/c on the idle drops way down and the engine will die some times when pulling out from a stop, will the IAC cause this to happen or is there alink in the wiring connection for the a/c switch that is effecting idle speed?

 

When the a/c is on, the PCM should adjust the IAC to compensate for the excess power draw. It's fairly normal for idle to drop a tad, and if you are easing out from the light, it will take more throttle than without the a/c on. If the PCM gets a WOT signal (>80% or so physically open), it should cut off the a/c temporarily.

The IAC valve and passages tend to get goopy over time, thanks to the EGR system. Pulling the TB off and giving both a good cleaning (carb cleaner and q-tips) should help some. If the IAC was actually malfunctioning, you should get a CEL and be able to pull the code.

Best of luck!

 

I discoverd the problem with the rough idle etc. was platinum spark plugs, we put them in not realizing some neons do not run well with this type of plug, but it took 38k miles to figure it out, also, gas milage had been way down as well as performance. We did clean the T/B, but it did not make any difference. The correct type on plug for the neon is located on a sticker under the aft/back side of the hood............

 

Single platinum plugs don't work well in any Neons, or any DIS car in general. Double platinums (prong and tip coated) work fine, but why pay 8 times as much for plugs that last twice as long as plain ol' coppers? Glad to hear you're running fine again.