00 2.7t start problem. Sensors? Pls help

I have a 2000 a6 2.7t with about 65k miles.  I've had a few small problems, but for the most part, this is the most exciting of 5 audis that i've owned in my lifetime.

Problem: Car won't start right off.  The starter cranks and cranks, and nothing happens, then after a while of waiting, it will start again.  The wait time has increased considerably since the first occurance 4 days ago.  This has happend only when I've driven the car somewhere, then left within 10-15 minutes of arriving.  When i've had the car parked for over an hour, i haven't seen this problem (yet).  

Possibilities:  Well, since the gas tank is full, I know i'm not out of gas.  I only use premium and I use fuel injection cleaners regularly.

I'm hoping someone has experienced a similar problem and can save me the an extremely expensive date with the local audi dealerships.

Thanks in advance,

UtahSteve    

Water in the gas line possibly? This used to be more of an issue on non fuel injected vehicles. You might try a bottle of Chevron and see if it helps.


Joe

Your coolant sensor may be malfunctioning - it could cause the ecu to adjust the timing if it thinks the engine is cold when it isn't.

But it could simply be your coilpacks; have you had them replaced at all during the 65K miles?

these symptoms EXACTLY match the failed fuel pump i had in my 100cs. i got the pump for about $200 and (in the old audi) took about an hour to put it in. this was a lot of aggravation because on longer trips the car would not restart for over an hour, and i had it towed several times only to have it start right up for the mechanic. give me an update when you get the chance.

What was the final DX on this? Did you get it resolved?