IAC valve?

[dj_joker_2002]

Anyone ever had a problem with this device? and is it the plastic thing with two screws and an electrical plug?

[kings-x59]

The original IAC on by '89 went out. the pintle on the replacement gets dirty from time to time and has become a regular maintenance item of mine. Assuming we are talking TBI here, the plastic thing with the two screws is probably the throttle position sensor. The IAC on my engine threads into the passenger side of the throttle body, very close to the TPS.
I've had problems with the TPS in the past as well.

[dj_joker_2002]

Yes sir you are correct, I swapped the iac valve and it did fix part of the problem, however when I first start the engine it still idles pretty high somewhere around 1900 RPM and when I put it in gear it drops down, any ideas? Mark

[kings-x59]

The engine should idle a bit high when cold, 1900 rpm sounds a bit much though.
When it's warmed up, does it still idle high?

check the throttle plate to ensure it is clean. If it doesn't close all the way, the engine will idle high.
A malfunctioning TPS can cause a high idle, but your SES light would be on.
Another possibility is a vacuum leak. A vacuum hose, or between the throttle body and intake manifold - gasket may be munged up. One hose I found loose on mine that was not readily apparant went down to the vacuum chamber (black plastic ball). Also check the hose from the evap canister all the way back to the gas tank. One section of this hose on my van was a hard black plastic that had a 1/2" long chafed hole in it. use your finger for those parts of the hose you can't see. check them all.

[kings-x59]

one othe thought, check the springs on the throttle linkage to make sure they are closing the throttle plate all the way as well.

[dj_joker_2002]

I found one of the injectors is spraying all wrong and dripping, I think it may be the problem.

[kings-x59]

At the very least it is contributing to the problem. I saw your other post after I wrote my little discertation. You've most likely found the problem. If cleaning the injector does not work, I recommend being careful about where you buy a replacement. I bought remanufactured (rebuilt) injectors and installed them only to find out they were stuck wide open as well.