[Porsche9]

Originally Posted by lkchris

Any gasoline engine requires a bit richer mixture to run when first started cold. Along with this it requires a little more throttle than is normal for warm idle.

A vacuum leak will undo this.

But, most cars of this era feature something called the idle control valve, whose purpose is to bypass some air around the maf to create extra idle speed. Mixture is richened electronically based on a temperature sensor.

So ...
Vacuum leak
Idle control valve
Temperature sensor

My guess is that it's one of the later two. The engine stalling and then upon restart running fine to me would rule out a vacuum leak as that would not go away upon restart. It didn't do it at all tonight some it looks to be intermittent.