I m needing some help here guys, I am dealing with a 97 Z with a procharger on it. everything seems to fine with the exception that when it is being driven it wont come down to idle. when you are sitting still you can free rev it and it will drop back to idle, but if you are moving and just drop the clutch in she will idle about 2-2500K?? any thoughts or suggestions on this??

 

Talk to Bryan at PCM for less. That sounds like a tuning issue. Could be a vacuum leak but not likely. Also your DFCO must not be adjusted for your cam or it would not go to 2000-2500 rpm without cutting fuel to the injectors.

 

thanks, the one thing that sounded odd to be was that it was speed related. if its rolling it does it, if not she does just fine.

 

For reference, any stick car will show an increase of idle speed if you push in the clutch at different speeds. More IAc counts the faster you go.

In the LT1 PCM, the idle air motor setting follows the road speed to make the transition smoother when easing on & off the throttle. Your throttle setting may be off causing this (due to a different throttle body) or engine mods have caused your tune to need corrected.

Do you know what your IAC counts are at idle? Let me know & I can give some recommendations to help correct.

 

When you come to a stop, does your idle drop back down.

Check your throttle and try to return it to its detent. Is it at 0% throttle? You might need an extra spring.

 

just saw this post. incase you havent fixed it yet I have a question: Have you cleaned the TB lately? When i did, my car did the exact same thing and I thought it was the IAC. turns out when you clean the TB some of the gunk that was sealing the throttle blades is now gone = more air to the motor at idle. Try closing the TB blades a bit with your allen wrench. That fixed the problem for me!