E30 Vapor Lock?

My wife has a 1990 325i that has what looks like symptoms of fuel line vapor lock. When started cold, it's fine. If it sits longer than 1-2 minutes after warming up and you then try to restart it, it starts up for a second, then dies. After 2-3 reenactments of this, it then runs.

My theory is that the fuel line is getting too close to the exhaust somehow, therefore vaporizing the fuel inside the line. After the car cools back down completely, it starts normally.

Is this very common, and what can I do about it?