I have a 4 wire IAC that I bought from EMI along with the mounting block also. I had set up the IAC as per EMI manual and the motor wasn't sealing off against the seat when I thought it should be so I made a new mount block where I can watch the motor move. I see the motor retract the stopper at startup like it should and as I rev the engine it starts to extend, closing the stopper, again like it should. then as the engine rpm continues up it opens back up (I couldn't tell rpm as I was watching the IAC but I'd guess near 2500 rpm). It seems to move in and out slowly above that rpm but doesn't reach the seat. The 2 rpm settings (per the popup help in wintec) say to set one close to idle and the other near your shift point. Idle one is set to 1000 and the other is set to 2000 (my shift point is way higher, 8200 way above the 3900 limit). I've left the min/max duty cycle set to 50/185 and haven't changed any of the other settings. The only difference other than the rpm settings is that I made the new block seating surface .5mm shallower than the EMI block. I've read the section in the manual and am not sure what to try. Any help would be great. I'd really like to use the IAC if possible

I had a similar circumstance and set the max duty cycle about 100 steps more than the minimum and it closed fully. Give it a try, can't hurt, maby it is your cure also.

The IAC does close but then opens back up. When it opens back up it moves in and out slowly, not being all the way open or all the way closed, kinda in the middle half of its range of motion. I tried going down to 3 on the min and up to 250 on the max and also both at the same time. It didn't seem to have much effect so I went back to the EMI recommended 50/185. I hate to disable it as it really helps on startup and idle, just gets goofy after that. hard to build any boost when its open.