[Jerry Bransford]

Probably leaking from not getting it seated properly or the o-ring was damaged or is missing. You didn't have to disconnect the battery at all to install a new IAC.

 

[JackBurton]

i actually just solved this problem myself in the past 15 minutes since i wrote this. i started it up and it immediately jumped in rpms, about 2k. then i suddenly remembered back to my motorcycle fixin days, one time i had a high idle problem i solved because the throttle cables were stuck. so i kept the engine running and played with the throttle body....and wouldnt ya know it, it was stuck.

i wd-40d the throttle body are and the idle immediately dropped to a steady 800ish. guess it wasnt the IAC after all. good thing it was only 15 on ebay, and now i have a new IAC

 

[UFOtestpilot]

...good thing it was only 15 on ebay, and now i have a new IAC

If it were me, I'd reinstall the factory unit and return the other. Unless you got a Mopar unit for $15 that money will be better spent elsewhere and it'll save you from having to deal with it when it fails while you're out and about.