Yeppers I've tried all sorts, including different Idle Control Valve, new intake bellows, I have also dismantled (but not mucked about with) the AFM. Could be a viscious vacuum leak somewhere, but would that cause a flat spot too? Maybe that's another problem entirely!
You have to remove all the intake to get at the vacuum hoses right? Do they really cause problems that often? Really I'd like to get hold of someone with a known good AFM/ICV and swap them over to see what happens. SO WHO LIVES NEAR ME WITH AN iS AND WANTS FREE BEER!?
Neil