I have a w-reg (2000) a4 2.8L quattro (geartronic), which over the last month has developed a fault when the engine is warm.
Starting engine from cold is fine.
Attempting to re-start engine having driven anything from 1-15 miles is not so easy - and it does the following:

1st attempt: turns over, but won't fire up
2nd attempt: starts, but revs either so low they are off the scale (<100) or too high (1200). The car then either refuses to do anything when i press the accelerator (the car won't move), or it stalls.
3rd-5th attempts: as per 1st attempt (turns over, but won't fire up)

Eventually (3rd - 5th attempt), car will start and i can get moving.

2 garages have run diagnositcs on it and found nothing.
I never see any error codes on the dashboard.
Recent service found nothing.
Spark plugs have been checked.
Thermostat has been checked.
Oil guage barely moves (generally sits on the minimum bar of 60 for hours, before eventually crawling to 62)
Coolant sensor had intermittent fault, so was replaced...but fault still occurs with the starts.

Any ideas would be appreciated, as i'm now looking at taking it to the main dealers for "better diagnostics", even though i hold no hope they can diagnose a fault.

Thanks in advance,
Carol

 

I used to have this EXACT problem and resorted to filling up my gas tank at night when there were less people waiting behind me.

Have you checked your starter or solenoid? I had my headlights unknowingly wired to my starter, which was draining power and basically frying the starter/wire. I would have your mechanic look for a failing starter. Once fixed and replaced, I haven't had a problem since

 

I haven't checked the starter motor or solenoid valve yet.
Will get onto it.
Thanks for the suggestions.