I was working on some idle issues with an 01 vette today. We having trouble with the RPM's hanging when pushing in the clutch while moving. I tried adjusting the Throttle Cracker Airflow {B4309} taking the 1000 and 1600RPM rows to 0. I also adjusted the decay rate up to get it to drop down faster.

Sometimes it works great, and the car runs normally and other times it hangs. When it does hang, it stays at that RPM until I reach 1MPH. I changed the TC start/stop to 6/5, and it followed those speeds. I am not sure what else to change to get the RPM's to CONSISTENTLY drop down to idle. It seems worse after shutting the car off and restarting it. Once driven for a while it gets better. You can see in the logs that the TPS drops down when the RPM drops down, so I don't think that it is a timing issue.

Any ideas of parameters to log?

Here is an example of a log: coming off throttle - RPM hangs until speed is 0 (I thought is was at 5 while driving) then TPS and RPM come down.
Click image for larger version.  Name: Idle.jpg  Views: 238  Size: 295.1 KB  ID: 10690
C5_Idle_0011.tun
Idle_00012.efi


Thanks,
Matt