7M-GE Strange Idle Problem

[nibaumer]

so, I have an 89 N/A 7M. for some reason, I get the engine up to operating temperature, and i cannot get it to idle at 700 (factory spec.). it idles at about 900-1000 and if I lightly touch the throttle, the idle will climb 500 and climb 500 again if I lightly hit the gas. It will stay idling high until I give it more gas and it drops back down to 900. Its not throwing any codes, I just tore apart the intake manifold and cleaned the throttle body and replaced all the gaskets. I did a full tune-up and adjusted the timing. The tps is correctly adjusted and i know there's no vacuum leaks. what systems should I check? What could be the cause?

 

[hvyman]

Did you check the idle speed control valve?

How is the throttle linkage?

 

[mecevans]

There IAC should click a few times right as you shut the engine off.

 

[nibaumer]

Did you check the idle speed control valve?

How is the throttle linkage?

I checked the throttle linkage, but i still need to run a diagnostics test on the isc valve.

 

[nibaumer]

There IAC should click a few times right as you shut the engine off.

It does that, but it still may not be working properly right?