High idle after driving

[S.hafsmo]

Yes, another idle topic.
My recent test drive revealed a few issues, and increased idle after driving is one of them.
When starting the car cold, it idles fine at approx. 7-800 RPM. At this point I can rev the car, even drive a little, but after it has reached operating temperature, it will not return to proper idle after driving or revving the engine. It's almost like it sticks to the coasting idle (1200 RPM) and won't return to normal.

It serves to mention that I've just been doing some work below the plenum, and I do not know if this was an issue before this work was carried out.
All gaskets are new, as well as all sub-plenum vacuum parts (hoses, grommets, actuators etc.), and I have eliminated most of these as the culprit by blocking of their vacuum supply. And regardless, would not a vacuum leak be unaffected by engine temperature?

I've also had the throttle body off, and while having it off, I checked if the DAG material was still there, which it was not. But again, would this be affected by temperature?

Found the primary throttle blade to be a bit small. This can't seal very well.


I've checked the IAC, and it does close properly.