poor idle surge and stall when cold

[AVIDMOTION]

Do we have a Idle air control valve ? If so where is it. On cold days in am the car when in drive and I come to a stop wiLl jerk, surge then stall, starts right back up and will do this until warmed up like the first 3 min or so. I ran two tanks of fuel injection cleaner, cleaned the hsrk sensor, cleaned air filter and cleaned out the maf. All were dirty but did not stop my problem. Only happens when cold out and not warmed up. Any help appreciated.

[Napalm]

How long have you had all those mods on the car? were they all on last winter?

did you mod your tune in the last year?

have you replaced your spark plugs and/or wires recently?

finally relative temps when this occurs - IE is it in the 20's or the 50's?

I'd start by saying you either A) have a bad spark - and when the engine warms up it gets better, or B) you have something off in the tune.

outside - possibly a bad fuel injector, but that should show up.

[AVIDMOTION]

Same tune for 2 years, same mods for 2 years, new plugs 3 months old, new wires 3 months old, happens below 40 degrees, only first 3 or so mins, then once warm no problem....

[AVIDMOTION]

Update, found a 3 inch Crack in the plastic vacuum line from pvc to billet oil catch can. Temporarily I taped it up. Unfortunately it only helped but still does the stutter stall surge leap during
todays 38 degree day, it did it twice then not the rest of the day. Once 3 min goes by it becomes a nasty responsive four daily driver. It just that first am start. Do we have a IAC valve? And if so where is it, can it be cleaned or cheap to replace? Anybody?

[G8 GT V8]

No IAC valve that I'm aware of. Is your throttle body clean where the throttle blade seats? Also, is your maf and air cleaner clean? At start up, the ECM commands a rich AFR so perhaps theirs a slight air blockage and its getting "flooded".

[AVIDMOTION]

Yeah crazy paul mentioned no IAC valve since like 2005 or something it is in the tune. Did a quick maf clean and air cleaner too, probably needs a better cleaning then. Did two tanks of injection cleaner. Put same tune back in but bumped to 725 rpm for winter. With UDP with defroster and all accessories on would dim. Since finding the Crack in vacuum it much better, but still does it until 2-3 min of warming....

[STAGEUP]

Did it surge last year in cold weather, with the same tune?

[Napalm]

the IAC is not a function of the full thorttle vane. it's in the fine control of the motor that runs the throttle vane. IE why have more stuff when the computer if runing that vane all the time.

I wonder if maybe something else is just a touch loose - like the air box, air tubing, throttle body to intake. etc. might check all bolts and clamps are snug - especially since you had it all apart.

otherwise I'm stabbing in the dark. but the warm up thing almost sounds like there is a minor leak somewhere that is closing with all the parts warming up.

finally and I hate to ask - intake manifold?

[AVIDMOTION]

Hope it's not the intake, I sprayed with water looking for hesitation but found nothing. Only thing I see maybe is the throttle body flap not shut flush when car is off. I gonna clean the TB very thoroughly and tighten everything up good. Mpg is suddenly horrible also. But runs strong. Ran a plx device scan no codes in memory all parameters ok.

[STAGEUP]

Did it surge last year in cold weather, with the same tune?