[s-cars] '95.5 S6 Fuel gauge problems -- SOLVED

[William Perron]

Erratic/innaccurate fuel gauge summary - no particular
order
Lister suggestions/ other research
1.  Try Techron in the tank for a possibly gummed up
float/sender
2.  Clean connections at top of pump sender/
assembly(outside tank)
3.  Clean ground at left rear tail light -- I found
reference to an Audi TSB on erratic
	or non functioning fuel gauge TSB # 90-94-06
4.  Wire becomes frayed in sensor/ float assembly and
must be repaired
	http://www.robsaudiworld.com/fuelrepair.htm
5.  Clean Fuel gauge sender connector inside tank
	http://www.audiworld.com/tech/elec.html
6. Test gauge by disconnecting pump/sender connector
at fuel pump access
	panel.  Jump sender connection terminals at wiring
connector.
	40 ohm resistor across terminals should read full
(ignition on)
	280 ohm resistor should be empty
7. If doing #6, gauge shows correctly- sender is the
problem
8. If #6 does not show accurate gauge readings,
problem could be in the gauge or IC
	circuit boards- I didn't get that far.

On my car, I tried #6 first to see if the gauge read
correctly, it did.  I then tried #2 and #1 with no
luck.  Turned out my problem was #3.  After cleaning
those grounds with really fine
sandpaper and some Caig DeOxit red contact cleaner,
may gauge seems to be working correctly - 2 fill ups
now.

Thanks to Kirby Smith, Bob Myers, Mark Turczyn, Jim
Klein and anyone I missed for suggestions.

-Bill Perron
'95.5 S6 Avant
'85 4kq
Burlington, CT



Original Message:

Message: 5
Date: Fri, 15 Aug 2003 11:51:48 -0700 (PDT)
From: William Perron <w_perron at yahoo.com>
To: s-car-list at audifans.com
Subject: [s-cars] '95.5 S6 Fuel gauge problems

Hey guys,
Having some problems with my fuel gauge on the last 2
fill ups.  Gauge will usually not go past 3/4 of a
tank even w/ fuel almost coming out of the filler
neck.  Gauge behaves normally from there:  autocheck
warning light triggers at same point it always did
(approx 17.5 gal to fill from onset of light).  Seems
like the 3/4 mark is now "full"  --for example the
gauge doesn't just hang at 3/4 tank for a while then
start dropping as the tank empties past the actual 3/4
mark, rather it starts dropping from 3/4 immeadiately
after filling- like it normally would from the Full
mark.   Seems to me that the "full" calibration is
off?  Can this be adjusted?  Unfortunately my Bentleys
are still boxed up somewhere(just moved). Saw a few
posts in the archives on replacing the tank sender to
cure some fuel gauge craziness. I'll probably start by
checking the connections at the tank.  I'm assuming
this would be in front of the spare tire  and
underneath the 3rd seat storage space carpeting
(avant).  Any other things I should check?  Do the
actual gauges ever go bad?

Thanks,
Bill Perron
'95.5 S6 Avant
'85 4kq


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