hindswillrox

You may have read my thread (Rough running /stalling after new alternator)
Well I am finally back on my feet after surgery on my broken foot so I was able to start further testing, The first thing I did was replace the fuel filter as I is almost due on the maintenance schedule then I went ahead with testing the fuel pressure at the fuel rail. When I removed the fuel lines I felt it to be odd that NO fuel dripped out at all,I could hear air rushing out but no fuel. So I connected a hose to the lines and cycled the key on and off, No fuel at all was pumped out. I can hear the fuel pump cycle on for about three seconds but I guess it is not pumping. does any one know if I can replace just the pump or do I need the entire Assembly, I see the assembly on line for around $700. Any ideas. And thank for the input on my previous posts.

silverd2

Pumps can be had seperately according to others including:
Post # 2, TozoM8
https://www.audiworld.com/forums/sho....php?t=2783947

Never had a problem with fuel delivery in my Audi A8, so haven't researched it much.
In an older VW golf, I had a perfect fuel pump I could hear running, but no fuel at injectors. Turned out to be a check valve that was letting fuel return to tank AND letting pressure back off immediately back to the tank and getting huge vapor lock in the main fuel line to engine.
Don't know if the A8 has a valve or something similar somewhere in the system that would not get pressure to the front when pump is working...maybe even in the pump assembly...don't know, but would be worth askin someone like tozoM8.