Hello. I have a 1999 XJ. It recently started having issues idling. When the motor is cold, and i first start it up, rpms will go up to the first hash mark, say 250-300 idle roughly and then turn off. If I hold the throttle a little bit to get rpm to about 1000 and the motor warms up, it will hold idle at that 250-300 range and won't turn off. Jeep runs fine when driving as well.

I pulled the throttle body and cleaned it, wasn't real dirty. J also pulled and cleaned the iac. It was black and so was the case. That didn't seem to help. I ordered a new iac from rock auto as they weren't all that expensive,, but any other thoughts on what I could try while I wait for it to arrive next week?

 

Well, you are off to a good start. But remember, always the basics. Plugs, rotor, wires. When was the last time you had new ones, or looked at them? Also check for vacuum leaks, though that usually results in a high idle. Test the TPS, too.

 

just changed plugs, wires, cap and rotor this morning. No dice, so stalls when the motor is cold and idles low