2010 Camaro idle no response

[SPi]

2010 Camaro L99 w/cam and magnuson, long story short, this car came to us from another shop and was a complete mess, we have rebuilt the engine, and repaired countless other issues from poor workmanship. The car is now running well and makes very good power. Driveability is also good with the exception of the idle. No matter what I try it seems like the car will not respond to any changes in the idle tuning. It always idles at around 950 rpm. When we received the car the tuning was so far out, and changes had been made in places i have never seen, we have had to dial in so much other stuff I'm just thinking I am missing something obvious, the car doesn't seem to care where I set the idle it just stays at 950rpm all the time. Other than that it runs great, any ideas guys. Thanks

[gmh308]

2010 Camaro L99 w/cam and magnuson, long story short, this car came to us from another shop and was a complete mess, we have rebuilt the engine, and repaired countless other issues from poor workmanship. The car is now running well and makes very good power. Driveability is also good with the exception of the idle. No matter what I try it seems like the car will not respond to any changes in the idle tuning. It always idles at around 950 rpm. When we received the car the tuning was so far out, and changes had been made in places i have never seen, we have had to dial in so much other stuff I'm just thinking I am missing something obvious, the car doesn't seem to care where I set the idle it just stays at 950rpm all the time. Other than that it runs great, any ideas guys. Thanks

Have you had a chance to read the definitive idle thread:

http://forum.efilive.com/showthread.php?9740-E38-idle-tuning

[SPi]

I did read through most of it, and did try a few things but I'm not having an issue with idle quality yet, it is the idle speed that is the issue right now. I can make the car idle lower in DVT mode, but it will not idle where it is told when running./?????

[BowlingSS]

Did you ever fix this idle problem? What did you find out?

Bill

[SPi]

Yes, I was finally able to get this to idle where I wanted it too. To be honest I'm still a little confused on the solution though. I thought I was going crazy, I spent so much time going through the tune trying to figure out what I was missing and couldn't find anything that made sense. I thought for sure that I must have been missing something as I was able to control the idle speed in DVT mode, which told me it was not a mechanical issue and the problem was with the tune. I did not have the stock tune for this car but I did have one for another customer's car I did a few months ago with the same O/S. Determined to figure out what I was missing I compared the two tunes and slowly started switching the values of the existing tune to the new one hoping to find out exactly the parameter that was causing my problem. Ended up I had updated all the values over to the new file(basically scripting the tune-the long way) and the car idled exactly where I told it too. I have no idea what would cause this. The only thing I can think of is that whatever software that was used by the other shop had a parameter that EFI Live does not have, so I was unable to change it or find it?????? Does this make any sense?? The car runs great and was delivered to the very happy customer, so that is good, but I would still like to know exactly what the problem was, or if anyone else has run into this before.

[VEV8]

my guess would be airflow related.. Airflow correction coolant multiplier

[swingtan]

It would have been airflow related for sure. My first guess would have been that the throttle blade had been drilled with too big a hole. But if no hole, then it was the commanded airflow or one of the correction tables. Just remember that when tuning the idle settings, these ECM's learn very fast. SO reset the controller after each flash just to be sure. Another option is to zero out the Idle Proportional Step Size table.

[SPi]

All airflow tables between the two tunes were identical. Still think of this sometimes, never did figure out what was going on with the tune the car had when I received it.