cant get idle below 1000 rpms

Champ10187

Founding Member
Dec 30, 2001
770
0
0
Detroit, MI
I just threw a new motor in my car which includes a vortech s-trim and when i started it up the idle was real high like 1500 rpms. When i go to reset the idle with the IAB disconnected it starts to surge up and down. at 1000 rpms its steady but as soon as i turn the idle screw to drop it anby lower than 1000 its starts to hunt up and down between 500 and 1200 rpms. If i leave it at 1000 with the IAB disconnected and the connect the IAB back up again and start it up it idles at like 1300. what the heck is goin on. I dont think its a vacuum leak because it can have a steady idle but only at 1000+ rpms. please help
thanks