I have had this annoying problem where when I start my car, no matter if it's hot or cold, the engine will rev up to about 1500-1700 rpm and come down annoyingly slowly to normal 850 idle. Before the blower, it would crank up and with a second or two it was idling at 850. All I put on was the blower and the crane hi-6 ignition and sicne then, the ignition has been changed without having an effect on this problem.

I have thought about one of two causes:
1- ****ty bosch bypass valve
2- I may have moved the IAC pintle in slightly when I had the throttle body off during the blower install (cleaned everything up). Is there any way to resynchronize the pintle position with the step number on the computer?

What do you guys think? Am I on to something or are there other things I need to look for?

 

When I cleaned my TB, the RPMs started to hang. Dab some oil on the butterfly rod as it enters the TB housing...issue solved!

 

Sounds like the IAC to me. Try resetting it by cranking the car with part throttle, let it run for 5 seconds, turn it off for 10 seconds, then restart it. it *should* fix it.

 

Get rid of the Crane. I removed mine and actually picked up power. MSD makes a better box.

 

I changed to an MSD Digital 6+ and now I am using a Delteq. The throttle is not physically sticking. Will resetting resynchronize the IAC and the computer???

By the nature of the IAC motor, it can't give feedback to the computer as to it's actual position. It merely counts steps up and down and hopes that it doesn't get out of position. That's why I'm wondering if resetting will do what I need it do (resynchronize).

 

If you have datamaster or freescan you can look at the IAC's position at idle and adjust it to get close to .5-.55 by sloting it. Hope this helps

Mikey

 

Amazing... I reset it and it actually worked this time. Counts are around 45 at idle cold (1100-1200 rpm) and it does not rev up at idle... I have tried to reset it many times before, I think I was holding the gas open too long. Shoebox's new guide has a really good and easy to follow method. Thanks again Rob!!