My problem is also similar!
I have a toyota soarer/lexus sc400. WHen I start the car (mainly when it is cold) it runs for a few seconds then stalls. There are no warning messages or anything. SOmetimes it takes up to 8 tries before it runs normal. GEtting the revs up do not help either. I heard it may have something to do with the air intake control or something, but not sure. Once the car actually is running properly, then its fine. The problem also sometimes happens after 15mins when it is still relatively warm...but primarily when its cold.
Does anyone know what would help fix this problem.. ? Thanks guys!