S185 Cold Blooded

My 1990 USDM Alltrac starts brilliantly every time, regardless of ambient temps.
The problem I have always had is it stumbles badly when cold for about the first mile, then it smooths out and behaves like a normal turbo car. My other turbo car is a 93 MR2 and it never dies this.
Any suggestions? I searched but, no dice.

This reminds me of my old '90 that I had to sell in 2009. I don't know, man. I think there were probably some innate issues with this car, possibly in ECU programming. Does yours seem to get better acceleration with the throttle at 8/10ths rather than flat out? I eventually accepted both as quirks of the car, though it's possible it's due to something known and someone more knowledgeable can chime in. If not, it would be interesting to run an aftermarket ECU with a laptop/iPad and all that and start making some tweaks to see if you can fix it.

You should try adjusting the maf. It will limit boost when the engine is cold but it shouldn't stumble.
I got mine to -31F and it runs perfectly fine.

Driving the MR2 again, while my Alltrac chills in the garage. Maybe I'll swap MAF's just for giggles. To be honest though, I am starting to suspect the ISC, too. My idle is all over the place , even when it is warmed up.

Okay. I think I fixed it. Need more road tests to be sure, but I think it is the Tial BOV.
PO installed it, presumably as part of the FMIC installation. Still sorting out other hoses and stuff, but this is looking like the culprit. Anybody know how to tig weld aluminum in the Seattle area?