This is a Ls3 to LSA conversion running 6lbs of boost. I have had this issue for awhile now and can not place my finger on it. When first starting the car when cold or even after running it for awhile, so engine warm just shut down and then restarted, the car upon take off runs lean for about 30 sec to 1 min til it goes into to c.l. mode. I have tried adjusting open loop gas gear mode, I have played with the transiets fuel mass gains impact factor. The other part is while the car is warm in c.L mode it will then switch to o.l. mode while at an idle for a period of time then. When it goes into o.l. mode at idle it starts to run lean until it switches back to c.l. mode. THe fuel trims at idle in c.l. mode are around + or - 2, 3 percent.
Here is a quick scan on a cold engine take off.cold lean take off gas.hplcold lean take off gas.hpl