plastic nut is fine... i cant find any vacume leak

 

did you take the intake manifold off

 

It's gotta be a leak then man. If you unplug your IACV, and it still stays high, and the FIAV (fitv to some people) is good, then it's gotta be a vaccum thing, or ecu related maybe.

Try resetting your ecu. Tell us more exactly what you did?

 

When you adjust that screw, the ecu is compensating for the adjustment, which is why you don't see a change. You need to jumper the service connector like you do when checking for fault codes. You also do this to adjust timing BTW. By jumpering the service connector, you're disabling the ecu and it won't compensate and you should see a change. Try this simple task first before the other more complicating tasks.