alright, i just recently bought a 5000CS quattro, it has this problem when you get on it to speed up, once you left off the gas, it will diesel out and shut off, it's a gasoline engine, we found a vaccuum hose that seemed to be unhooked, so we hooked it back up, once we did that it was idling anywhere between 2000 and 2500 rpms, any suggestions?

you got a bunch of vacum problems http://www.audiforums.com/m_390931/tm.htm ... then clean out the ISV then check for all temp sensors to be in good working condition

i would say it could be that, but it idles fine, and runs fine until you tromp on it to pass someone, as soon as you let off the gas it drops rpms and stalls out.

you might also be suffering from a sticky deacceleration valve .... but in any case fix all tha vacum leaks first ... it is the cheapest and esiest fix you can do

I have had some of the same problems, I think I need to look for more vacuume leaks and such, any thing else it could be??? I have replaced the hall sensor, warm up module, all of the temperature senders, and many other things...That is where I will be headding next...This thing has been out here in the desert for many years, and I know there are alot of things that need replacing...but I really love the vehicle...I hope you find out what is giving you the problems...If I find any thing else on mine I will forward it.. THanks

Turbo Rhatt