BMW Repair: 99 E46 328i, 5 spd. cold idle stall/shut off, engine sensors, vacuum leak

Question
This thing is driving me nuts. Since I bought the car in 10/05 I have had a cold idle issue. When under about 50 degrees outside the car starts perfectly and idles up perfectly. It will run for 1 minute or 2 and then act as if it is going to stall and then catch itself and idle back up to normal idle. Once it warms up it is fine. I DO NOT have an CEL so I'm assuming not cam sensors. I have replaced IAC motor with a new Bosch unit and still no change. Exactly the same. I've been told it's a vacuum leak, VANOS or MAF. I know sometimes MAF's can fail but not trigger the CEL. Any ideas what is going on here? On a 10 scale my skills are about an 8.
VIN: KG10108
Build Date: 04/99

Thank You,

Brian L.
Nashville, TN

Answer
Brian, you need to get this car on a scanner or BMW GT1 to check the statuses of the engine sensors and see what is happening or changing when this happens. Did you check you intake boots for cracks and tears when you were in at the IAC. This does sound like an electrical issue since it doesn't happen all the time. I believe you need to get some diagnostics out of it, if it is consistently reproducible on cold start.
-Evan
-Evan