Low idle with a/c on

[chuckstsi]

So I did a search and nothing helpful...

Car idles fine under normal conditions. I've noticed recently that on the first start cold or hot it will usually stall. When I flip on the a/c it idles at 500rpm at best. Any thoughts?

 

[kingcoyote]

Hmm so its not just when the A/C is on ?

Sounds like your ISC motor is bad. Test it:
DmTaLoN's Idle Speed Control Test/Fix Page!

 

[chuckstsi]

Yeah, not to argue, its only when I start the car and only when the a/c is on. Every other time its dead on. I figure the ISC is ok...?

 

[volcomsnow245]

This happened to me in the winter when i would first start the car and put the heat on. My isc motor was perfectly fine to so im not sure why it does that? I have the same car.

 

[blcknspo0ln]

You may want to check your alternator power with/without the AC on. Just to eliminate another factor.

 

[chuckstsi]

So alternator is putting out 14 plus volts....

 

[blcknspo0ln]

Have you boost leak tested to 25-30psi? Have you tested ISC&IAC for proper operation? Have you properly adjusted your ISC? Is your mechanical timing correct? Is your base ignition timing correct? Are you properly tuned at idle? Have you checked ignition operation when warm (i.e., transistor, coil pack test differently when the engine is warm), etc.

Lots of stuff, this should get you going.

 

[Bud92gsx]

You can see that idle might drop 100 maybe even 200 rpm with the lights, heat or AC on..But idling down at 500 rpms, something needs to be replaced..