Originally Posted by Dvigna
I unplugged the iac valve and there was no change to the idle of the engine. I will look for loose or broken vacuum lines under the manifold when I get Time to take it apart. Could it be possible my iac valve is not working?
Remove IAC valve and then plug in its wires
Turn key on and IAC Valve should open all the way
Unplug the wires, while key is still on, and IAC valve will close
Plug wires back in and it should open again
Repeat a few times to make sure it isn't sticking.
Computer always opens IAC valve all the way for starting, thats why all fuel injected engine should have high RPMs on start up and then RPMs will drop as computer sets idle RPMs for engine temp.
Many don't notice this since they have their foot on the gas pedal.
Try starting engine without touch gas pedal to see if this happens