Audi Repair: A4 wont restart, vapor lock, fuel line

Question
I have an A4 99 with 130K Kilometers on it. When I start the car in the morning it starts and runs great. The problem is when I stop and have to immediately restart the engine, gas fill up, short grocery stop, quick visit to a friends house etc, etc. The engine turns over but does not start. When it does start it's after 20sec or so of just turning over, then it has an awkward idle for about 30sec. Then as if nothing happened the car runs fine again. There is one other thing, the car has picked up a diesel engine sound and it's just a 1.8 gas engine. By diesel engine sound I mean the knocky putter or rattle when the engine is on.

anything would be appriciated

tks
JoeKeno

Answer
The poor starting may be due to a vapor lock in the fuel line, or a tired pump.  Mine does the same but since it always does start, I live with it.  It is interesting, however, that this only happens when the engine is hot, when it is cold it starts immediately.  The diesel sound I'm not sure what you mean, this could be a chain sound or a valve?  Can you describe the sound better?

Jan