iac controller issue

[Ross gardiner]

i have a gm style iac valve that we believe moves perhaps under load boost , then the computer reads it open and alters the idle speed to fast and as it takes ages to reset and every time you rev it ,it goes hey wire 

we have tryed differant settings but cant seem to be making head way .but if i unplug it ,the computer  runs the car fine if itr is reset and closed correctly ?

will this be causing boost leakage >?

[Simon]

Shouldn't cause boost leakage as it will be taking air from just on the other side of the butterfly which would also be under boost.