poopaloop

for a few weeks now everytime i start my car it will start fine, idle at 1200ish for a few seconds drop to 900rpm idle for a minute or two then start going from 1500rpm to 500rpm just lopeing like it has a MASSIVE cam in it then after about 3-5 minutes of that it idles at 900-1000rpm like normal.

what is causin this? i cleaned th IAC and Throttle body but nothing happened. any ideas?

mods are...

89 gt, bbk CAI, UD pullies, bbk LTs and o/r x pipe, flows dumped, brand new msd cap, rotor, wires, coil (was doing it b4 ignition was installed), bosch +4 platinum plugs.

poopaloop

bump.

tmuti13

Check your vaccum lines

cdougherty

My first time offering advice... but I had the same problem and it's very likely your Idle Air Control valve. It happened to me and I replaced it and it all worked fine. I would definitely shop the IAC around though. I bought mine at a dealer and it was waaay too much $$. Check Mustangs Unlimited or the like... I think I saw it for around $75. Also, make sure you get the little gasket for it. Check my similar post on the topic.

jtmustang

iac valve take it off and clean it off and/or vacumn lines off or broken somewhere

poopaloop

mk ty guys