This fun never ends.

Okay. I put in a new IAC motor, and it idles perfect until it warms up and the MAP detects the huge vacuum leak I have at cylinder #3 on the manifold. Yes, i’m going to fix it this weekend. New bolts, studs, and compression washers.

But, ever since I got the new one put in, every time I start it in the morning, it only idles at 600 ish. It doesn’t idle high and then idle down, it just starts up and idles at 600. Sometimes it sounds like it’s going to stall with how low it’s idling at startup, and with the low idle I don’t get much oil pressure on startup.

The only thing I can think is that I need a new auto shutdown relay, which I think tells the IAC that it needs to idle at a certain RPM on next start up. Something like that.

Maybe someone can enlighten me.

 

I know this is an old thread, but it was because of a crappy IAC that I bought. I bought a cheap part, and got poor results.

The new MOPAR one I got instantly changed the idle, and after fixing most vacuum leaks, I now idle at about 700. Which from what I read, is what the 2.5 idles at. I could get it a little lower by putting some clamps on some hoses at the manifold.

Moral of the story: Just because it’s a Jeep doesn’t mean buy cheap parts. The PCM is very sensitive and if you install some crappy $10 part, don’t expect the PCM to react well

 

C.R.A.P. Chinese Replacement Auto Parts