2.3L ('83-'97) 2.3l high idle on cold start with AC on

[CyrusT]

I have 96 Mazda B2300 2.3l and a manual. On a cold start with the AC on the motor will rev up to 2500, but without the AC on it will start lower 1500 RPM. The RPMs will come down to 1100 quick enough without the AC on but with the AC on it will stay high for a few blocks. The AC will also make the RPMs go up if I turn it back on in a minute too. Not till it runs for a few minutes does it seems to run Ok with the AC on. I deal with it, but my wife can't.

 

[scotts90ranger]

Does the idle ever get down to a normal ~750-800? If not I think you have a vacuum leak somewhere. The IAC is working since it's idling up with the AC on but those speeds sound excessive, surprised you aren't getting a code for excessive idle or whatever that is...

 

[CyrusT]

Yes, it would idle down to 700 after a few blocks. It would even idle down when I would turn off the AC. I have read complaints about IACs. After, I cleaned the one on the truck with some brake parts cleaner, it did run a little better but not good. Since the motor was not running well I replaced the one on the truck with one from Rock auto. It did run better again but not good. Just for so I got the old IAC and shot it up with some PB blaster and put it back on.

Now, it starts up at 1500 and it shoot up to 2,000 briefly when the AC kicks on, then it will work back down to 1500 and then 1100. All in about 30-60 seconds, then it will ilde down to 700 when it gets going for a minute. I think it is as good as it will get now?

So, the complaints about IAC not being good seems to be true.