I have a Ford Throttle Body from a 4.6 car. The car car surges pretty bad. It probably goes to 1000-1800. I got it stable one day but when I turned the car off it started again. I just dont see how it could surge cause theres literally nothing there except a TPS. I was thing it might be a vacuum leak but I didnt find anything. There are 1600cc injectors in the car but ive seen a couple cars that idle just fine.

I know there are alot of people out there running these, and im sure there is just some simple fix. I just really dont have a ton of time to mess with the car.

You'll probably always be plagued with idle issues until you figure out how get an IAC motor back on there.

Did you ever figure the tps out? I am currently having the same problem

Considering he was last seen 4 years ago....