Make sure the manifold vacuum connections aren't leaking - get the engine running as slowly as you can, hold it steady, and restrict any airflow around these with your fingers. You'll feel the engine run more smoothly when you identify the airleak... if no change, chances are they're okay.
Make sure the IACV is connected, and working.
Did you re-use the gaskets between head, LIM and UIM? You may be able to spray a little wd40 in the area to (very) temporarily seal the leak, but access is pretty poor...
Daft question time - your timing is good? You've not left anything disconnected anywhere? The battery is fully charged? No tools left in the airbox? Checked the spark plug gaps before refitting?
Thanks for all the help. today I pulled of the intake manifold and clean the gasket surfaces and cleaned the idle control valve. I donÂ´t know which part were the failure, but now it idles smoothly :driving: