High idle issue with 102mm only in park and neutral.

[Maxspeed96ct]

Hey guys , 09 g8 here with a e38 ecm and 6l80, mild cam and LSA on a 6.0.

I know there is so many of these 102mm posts but help me out. I dialed it in pretty nice using a ETC scaler of 7400.000, my min airflow numbers are just above stock its great. Good manners in drive and cruising around.

I toss it in park or neutral, it idles high. It starts ok and then creeps or just stumbles. If I try to lower the minimum air it stumbles worse. Its like it tries to correct and just way over shots and then cant catch itself.

Watching the scanner the only issue I see is the TPS goes to like 2-3 %, maybe should I try a scaller of 7000 so i can have a higher TPS % and more control , just bump up the min airflow ?


Also I brought the over and under spark tables closer to 0, did I go the wrong way?

should I try to cheat it but lowering the idle air min in park and neutral but add idle spark ?

What else can I do, i feel like theres a spark table im not thinking of

would enabling spark smoothing help me ? white g8 rona best file so far but shit idle in park trial with new steps numbers from george.hpt

[Mr.z0611]

Return your overspeed and underspeed tables back to stock and test it.

[Maxspeed96ct]

Chased my tail for 2 days on this guys and it ended up being a vacuum leak.

I watched the throttle body slowly try to close in the log to bring idle down and once it hit .4 TPS the air was still high and car would stumble

Etc of 7000 ended up being the sweat spot though