96 GT 5.4 Swap Idle Issue?
 

I recently traded for a 1996 Mustang GT that has a 5.4 from an F150 Lightning I believe, with a biig cam in it, and I've noticed that on occasion it will drop the idle really low, nearly die, then it'll kick back up a little. Do I have to get my idle re-tuned? It seems really inconsistent sometimes, and other times, it's fine.

Could be in the tune, could be the IAC. We really need to know which 5.4L it is because the lightning was supercharged and it has more than one cam.

It was supercharged, but the guy who owned it before the guy who I got it from, took it off before he sold it. And then it was tuned after that. I didn't get any paperwork with it sadly.

Hmm sounds like an IACV to me as well. How often is this happening?

Could be the cams if it's really big and causes a rough idle.. Some cams make it to where the car almost dies or sometimes does die..