Audi: Fuel gauge and fuel smell problems (audi 100)

Hello,

In my Audi 500 (South African version of the European Audi 100), there
is quite a strong fuel smell, especially in the boot, after the care
was filled up.

In addition, the fuel gauge doesn't work properly any more. When the
tank is full, it shows just under 3/4. When the tank is absolutely
empty, it still shows more than 1/4, as I found out when the car
stopped (luckily 50m from home). The warning display and beep for an
empty tank also doesn't work any more.

Thanks for any suggestions,

Christoph

Christoph Bollig wrote: 
 

Under the car you can follow the fuel line along the frame on the
passenger side of the car. You will find rubber mounts all along there.
The problem is that water accumulates in there and can rust through the
line.
 

The valve is probably the fuel pressure check valve. On some years it is
part of the fuel pump. On others it is a separate black plastic device
close to the tank but separate from it. May be it just needs to be
tightened. The fuel pressure in these cars is high (60 + psi AFAIK)

Is the fuel pump and gauge accesible from 

Crawl into your trunk : ) and there is a plate under the carpet right
behind the back of the rear seat. Removing this plate gives access to
the in-tank fuel pump and the sending arm for the fuel gage. You don't
want to do this unless your tank is almost empty.

The fuems seem to come into the 

You may also want to check if there is a leak in the tank filler pipe.