Coolant Leak

[L1011tristar17]

Back when I picked up the car from the shop, the mechanic showed me that with the IAC plugged in, the idle was high but when the Air Charge Temp Sensor was unplugged, it dropped back down. He recommended replacing it with the old one from the other intake. I never had problems with the old one, but it looked pretty crusty to me. Lots of black gunk. I might see if the parts store has one in stock.

[sly]

also unplug the negative battery cable with you change it so it'll re-learn the sensors properly.

[L1011tristar17]

Fixed! I looked at the car this morning and did several things to it. I unplugged the battery for 20 minutes (per sly's suggestion) and during that time I looked at the vacuum lines. One of the fat lines wasn't pushed on all the way and another line was barely on! It looks like it was pushed on and the end of the hose collapsed on itself instead of properly sealing onto the nipple. I also cleaned the throttle body a bit as well as the IAC. Lastly I took off the throttle bracket and put it back on to make sure it was installed correctly. I started the car up and it idled a little high since it was cold out, but a lot lower than it used to. It drove fine as well and during the 20 minute drive it gave me no problems. Coolant temp sat right in the middle of M and stayed there. I don't know what fixed it, although I'm betting the battery and fixing the vacuum lines did most of it. Once again, thanks everybody for the help!

[sly]

yeah... cleaning the TB and IAC always tends to help with LOW idle, but the vacuum lines were indeed your high idle issue more than likely. Also, running lean (from open vacuum lines) will tend to make the engine run a little hotter as well.