I apoligize for the posting of the second thread, but the other thread isn't titled right.

My 420a doesn't stall, but it gets way to close. It has a very rough idle with alot of motor movement. It wants to idle at like 400 or 500 rpms, which is way to low. It'll get down there and then rev itself back up to 1k or so, and then it'll slowly work its way back down. My gas mileage has also gotten worse, I'm down to 23/24 when I was at 29/30.

I pulled the plugs this weekend, and nothing was wrong with them; I regapped them and put them back in. I also pulled the throttle body out and cleaned it out, nothing was stuck or clogged. I also replaced a piece of vacuum hose since it was cracked, but that didn't help either.

So I'm not sure what else to check. A new IAC and a new coil pack are both 80 bucks, and I'm not sure how to test either one to see if they are bad. Any suggestions on checkthing those two items? The check engine light isn't on. What else could it be?