IAC/idle help

[spederman]

finished my bullitt intake swap and for some reason my rpm's hang @1800 until i come to a complete stop then they go down to 1000rpm. If i blip the throttle while idling, it will hang at 1800rpm again and slowly come down.

If i unplug the IAC hose, the car doesnt die or stumbe, the rpm's actually go up and idle at 1200rpm. IF i unplug the electrical connector to the IAC valve, the car idles PERFECT @700rpm. The rpms dont hang at all, if i blip the throttle they drop instantly and the car stays running. Shouldnt it die without it? What could be wrong?

 

[trombonedemon]

Sounds like you have manifold leak to me, I'll tell you why, I put an intake spacer above the manifold and put the gasket on the wrong side, and it was pulling way too much air, and it took a while to settle to an idle.

 

[GDawg]

vacuum leak...