Hi All,

My 98 Neon has AC exceleration issues. I changed the PCM 3 times now and still speeds up when on to aprox 40 mph.

Can it be a bad compressor???

Are there any other parts that can be feeding bad fuel info to the PCM to make car excelerate???

MAC

 

Well Macloed, I have sort of the same problem. If I have on the defrost or AC on "sometimes" the idle will jump up to around 2 grand, or in my case it wont fall past 2000 rpm's when I let off the gas.
It has had me puzzled for almost 2 years. It cannot be the compressor becouse mine has no belt on it.
I thought that maybe that becouse I took my belt off it does it but I dont know.When you do get it straight let me know! GOOD LUCK!!!!!!!!

 

what do you mean by accelerate? Do you mean just a high idle, if so how high?

 

Its high Idle. But if i take foot off break at a light it can go up to 35-40 mph idle. That goes for heat or a/c. If i turn it off idles fine.


MAC

 

Sticky IAC would be my bet.

 

?????

Do you mean it will go up to 35-40 mph without touching the gas?

 

Yes without touching Gas...

MAC

 

With the A/C or defrost on, the PCM sends a signal to the IAC (Idle Air Control) valve to compensate - opens more to allow more air in. If it is sticky or otherwise failing (common enough), it will stay open longer than it's supposed to, which keeps rpm's up. So like I said, sounds like a sticky IAC.