Rough Start/Idle -- What's going on?
 

Way rough idle in the morning for about 10 seconds, sounds like it has a big cam and is stumbling. Local dealer has given up trying to figure out what the issue is. They acknowledge a problem, but cannot diagnose how to fix it. I've had my tuner try and up the cold start idle to see if that fixes it, but it does not. The car used to only do it every once in a while, but it now does it every morning regardless of temperature. It has now started doing it when I start it at lunch, and at 5 when it's quitting time but the idle is not as bad as it is in the morning. Berg said they checked the fuel pressure for the fuel pump with the engine off and it's fine. There is no black smoke in the morning like if it was associated with an injector leak, but I don't think I'd count it out. I've also tried loading a few different ECU maps with no change in the start-up condition. Anyone have any ideas what the problem might be? I have my mechanic getting ready to look at it, but would like to go in with some potential ideas as to what it is -- especially if it is something someone has seen before. Thanks for the help.

Mods -- Vector Tune, DT Catless Longtube Headers, Vararam Intake. Mods were on before the problem started. Stock ECM tune still has rough start.


[youtube]RyOHyIvsU78[/youtube]