yeah check for fuel ... jump the fuel pump at relay , disconect a feed line , the pump should give you 0.5 liters of fuel in 30 seconds if battery at 12 volts

 

Well, if its not your fuel pump, I'm just sujesting that you might have a vacuum leak. I had the same problems with my 5000. When I started it up, I would have to keep my foot on the gas pedal just to keep it running. After I changed a few sensors, wich that didn't fix it at all. It was poited out to me that I had a large tear in my air-intake boot wich led from the ail filter to the butterflys. All I did was patch the cracks on the boot with some silicon, I forgot wich kind. After it dried, I started the car right up and it idled.

 

Actually it turned out that i do have a vacuum leak. Right under the fuel distributor where it fastens onto the airbox. There is supposed to be a cork gasket, and the old one was shot.

Gasket maker and the old one did the trick.

 

cool beans it turned out to be a simple enough problem ... I check for vacum leaks with a can of brake cleaner ... the vacu leak sucks in the brake cleaner .. it burns really good so the rpm jump and viola vacum leak found ... well done man

 

That sounds like a really good way to check it.

Spent so much trouble checking everything on this car, when all along it was a little vacuum leak.

You gotta love audis, half the time the only thing ever wrong are leaks and bad connections