need help fast

[slick06emp]

ok so i got an safcII and started to tune but when i try to hold my rpms steady at 1000 2000 and up to 4k they bounce...kind of like a rev limiter. i know its not that but what could it be? IAC? my egr is blocked off..no vacum leaks. after 4k i can hold them steady but under that they build to the desired number but then fall down to 800 and bounce back up....any ideas?

 

[Colt4G63 also]

You could unplug the IAC. Set the lower RPM ranges, then plug it back in. It does seem strange though. I could see it doing that at 1000-1500, but I wouldn't expect that at above 2000. Although once the safc is set up right it might not.