76 Eldorardo, erratic fuel gauge

[RIchard Paley #1066]

About a year or so ago, the needle on my fuel gauge began fluctuating according to road conditions.  One can still tell the level of fuel in the tank, especially when the car is motionless.  It appears as if fuel, sloshing in the tank, is causing the float on the sending unit to "dance" around.  My mechanic pulled the tank, noted that it was "clean as a whistle," but that there was no baffling to be seen.  Yet he did not think that baffles were involved, as he believes the tank did not have them in the first place.  We then sent the sending unit out to a reputable rebuilder.  Upon its return, he reinstalled it and re-mounted the gas tank.  Alas, it did not correct the problem.  Any thoughts on this would be very much appreciated.  Thanks.

[Doug 22747]

the next thing to do is eliminate the wiring as the problem.  Could be a frayed or partially broken wire somewhere.  Not fun, but you should closely examine all the wiring involving the gauge.  good luck.

[RIchard Paley #1066]

Thanks for responding, Doug.  I thought of that.  But the needle seems to move only with the motion of the car, like the sloshing of fuel in the tank causing the float to bob up and down rather than to rise and fall gradually with the fuel level.  Think it could still be a wiring issue?

[denise 20352]

  Of course yout float is going to move around.  Baffles wont prevent that.  The float is just a variable resistor.  What keeps your gas gauge from bouncing around with it is "snubbing".  On a mechanical type gauge, snubbing is done with a restriction in a line, but a gas gauge is electrical, so the snubbing is done within the gauge itself.

  Try this...with some gas in the tank, when you first turn on the key, does the gas gauge go right up there, or does it slowly move?  It should take several seconds to move up to the fuel level...if it doesnt, I would try another gauge.

-denise

[Porter 21919]

FWIW

http://www.chevytrucks.org/tech/gasgauge.htm TARGET=_blank>http://www.chevytrucks.org/tech/gasgauge.htm

[JIM CLC # 15000]

04-23-06
PORTER, OK, Ill be the one to ask the dumb question. Just what does FWIW mean? Ive seen it in a lot of post but didnt want to appear too dumb by asking but your post proved to be the straw that broke the camels back.
Good Luck, JIM

[Bruce Reynolds # 18992]

Gday Jim,

I too hate it when people shorten things, but FWIW translates to "For what its worth"

Bruce,
The Tassie Devil(le),
60 CDV

P.S.   But, we have been doing it for years, even before text messaging came in.   Like, CDV being short for "Coupe deVille".   So, I suppose we cant complain.

[RIchard Paley #1066]

Thanks, Denise.  Your assessment makes sense.  Ill try the experiment and post the result.

[Richard Paely]

Your "snubbing" assessment seems correct.  As soon as the ignition switch is turned on, the needle on the gas gauge instantly reads the level.  Ill replace the gauge. Thanks, again.