anrtman

I have never had a problem with each and now i have both.Yesterday i changed the ACT and cleaned the throttle body a little.(i didnt remove the TB and know i should of)Im pretty sure that the new ACT has nothing to do with it but at first i had a hanging idle around 1100 so i cleaned the IAC and now it still hangs around 1100 for a few seconds then dips to about 800 and back up.The TB was extremely dirty and i used mass air cleaner and a clean towel gently to clean it.I dont know where to go from here.just moved so i dont have everything i need pull codes with me.Any ideas helpful.

saleenpride1986

On our model mustangs that is a common thing for the computer to do, hover around 1000 to 1200 for 2-3 seconds then drop back down to whatever the normal idle is. I had about six ford shops look into why mine did that and none could come up with a solution, so I looked it up and that's actually normal. It sucks but it's not wrong or bad for the car.

There is a way to bypass that but I don't recall exactly what the process is as that was a long time ago when I looked into it. I'll see if I can find the link to where I found the info to make it so it won't do that.

nseoi

welcome to the club :sigh:
egr was a big cause of mine. after i deleted that, it has gotten a lot better, but still slightly there

anrtman

any other ideas?It has idled perfect for years until yesterday.I will recheck all vacuum lines and lube the throttle linkage today

dcFalcons51

check your ten pin connectors

87Stallion

I used to have the same issue but a big Holley Carb fixed mine. No more surge.