Fuel gauge problem on Audi 80

A friend of mine has an Audi 80 1993 which has developed an intermittent fuel gauge problem. Sometimes works, sometimes not or sometimes gives false low readings. I had a quick look when the gauge wasn't working
and gave the top of the instrument panel a bang with my hand and the gauge started to move but very slow. Next to the fuel gauge I noticed an adjuster which according to the handbook says it is a fuel gauge adjuster only to be used by Audi technicians. You can just feel the tip of this adjuster sticking out of the plastic instrument panel so I gave this a gentle tap and the gauge started to work again. Does this sound like a loose connection somewhere in the gauge? and anyone know what this fuel gauge adjuster is for as I've never seen one before.
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never worked right despite attention from three Audi dealers. It stays on full till a quarter of a tank-full has gone, then drops, always showing a quarter more than is actually in there. I too have the adjuster but my owner's manual does not even mention it, though it's there in the photos. Sorry this was a "me too". Tom
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I have a 1988 90q 20V, if you turn the adjuster the hauge moves a litle bit. My guess is that it if for fine tuning.
tom_nospam snipped-for-privacy@pobox.com skrev:

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The only thing I can suggest is a change in tactics, learnt from the fact that I got my first car with a broken fuel guage. When I get a car I fill the tank up and reset the trip, drive the car till the guage says between empty and quarter of a tank, note the mileage, refil & reset, then if the guage breaks as long as the tank is full I've got a reasonable idea of how much fuel I've got as long as I fill the tank up each time.
I've got the 2.0i 8v (66l tank) and getting 350-400 miles per tank, 400 was very close to empty though (60 litres) but I'm not doing many runs, mainly around town etc so I'm not going to get high mpgs.
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Jon B
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