Low/lumpy cold idle w/ surging/bogging when driving cold

[azndeugene]

The car having issues is a 1988 325is stroked to 2.7. Has 885 head and 274 cam.

So for a few weeks now my car has been having a rough time in the morning. It starts up fine and idles at around 900 but if you drive out of the garage (~10ft) it'll get lumpy and drop to about 500-600 and then maybe bump back up. When you start driving it feels like it bogs/surges almost like a spark plug is misfiring, but once the car is at temp then everything is normal. It will idle at about 750-800 and drives smooth.

I have checked all over:
Sprayed carb cleaner for known vacuum leaks. I will be taking it in for a smoke test this weekend to double check and verify there is no pinhole leak I may have missed.
Intake boot shows no signs of cracks.
When warm, idle drops as expected when pulling the dipstick or oil cap.
Replaced the Cold Temp Sensor (blue)
Replaced Spark Plugs
Replaced O2 sensor
AFM is clean and was refurb'd by Bav Resto
TPS shows continuity for idle
ICV is clean and has been doubly verified with 2 different ICV's
FPR is replaced

Anyone else suffer through this similar problem? If I can't get it then it'll end up in a shop shortly since my other e30 is also down and I am without transportation.

Thanks

[Kershaw]

Have you done anything to tune for the cam and stroke? Maybe the stock DME can't handle the difference when it's cold. I know the cold engine tune is a different set of parameters.

Not a great test, but start it up and then remove the oil filler cap. See if it changes the idle any. If it gets worse it's probably not a vacuum leak. Also try unplugging the afm, see if that changes anything. Try unplugging everything, one at time, really, o2, cts, icv.

[azndeugene]

Yes, it has a tune for the cam, stroke and 17# injectors. Could the tune have fried? Seems highly unlikely.

I'll do some unplug tests later today but how would this lead me to why its struggles cold but performs fine when at temp?

[azndeugene]

So I got the car smoke tested and they did not find any leaks.
The shop's only remarks are that a heavy cam will have a poor idle when cold.

Does anyone with a 274 cam suffer a similar problem as me? I'm investigating because this was not how the car acted when I first purchased it so I deduce it is abnormal.

It seems like I may have to take my bimmer to a bimmer independent shop in order to get this resolved.