I haven't done any logs during startup/cranking but I was wondering if anyone knows or has any evidence of fuel trims being used to determine how much fuel to spray during cranking? Recently I've started seeing my idle LTFTs around -7 to -8% and my 08 GSR stumbles and sometimes stalls on cold starts. Is it possible that it is seeing those high trims on startup and choking itself with fuel when it tries to start?

Or maybe I've gotten some kind of leak that is causing both the trims to be that bad and also the trouble starting?

 

LTFT's won't be used during cranking.

 

Didn't think so but it was my crazy idea after spending the weekend staring at logs and tables in ecuflash, and trying to figure out why my car tries to stall when I start it sometimes.

 

If you think that is the case alter your LTFT low so that it is not used during very low airflow (like startup).

This is assuming you have adjusted your cranking enrichment tables properly, MAF is scaled, and ... well... that you get your LTFT in check!

 

Thing is I shouldn't need to change any of those... stock airbox with a drop in Perrin filter, high flow cat, and catback are my only mods.