i have done it correctly checking, dis connecting the iacv, leting it drop down to like 5 hundred or something and then adjusting the screw. the idle stays stationary at between 750-8. but it still does the putting. the b20 is supposed to idle at 750 +-50. and it has been. after the first few days that i got the engine put in, i changed out the spark plugs and it worked fine for about a day or two and then it started doing it again. everyone keeps telling me that its teh iacv. i hear no vaccum leaks, i have been told i would have heard it.