Freak'in Fuel Gauge

OK.....this thing is wear'in me out. I have installed a new tank,new sending unit,new wire from sending unit to connector in trunk and new fuel gauge. And for all that I still register 3/8 of a tank even though I filled the tank up. The one thing I just noticed is that when I disconnect the ground wire that runs from the sending unit to the body it makes no difference, the gauge does not move at all (with or without the key on). The only way the gauge will move is if I disconnect the wire that runs from the sending unit to the trunk plug in connector. It will go all the way to full ,but go right back to 3/8 when I plug it back in. Any assistance would be appreciated.

Unplugging that wire is SUPPOSED to make the gauge show Full, or a little over. I am currently having a very similar problem. New tank and a new sender from Classic Industries. I show 1/8 tank when full and when it shows empty I still have 6 gallons left. Look over in the electrical section.

I'll let you know if I ever figure it out and would appreciate if you could let me know if you figure it out.

Did you get your sender from Classic Industries too?

I have a similar problem in my nova. If I go put some gas in, and lets say I get 1/2 tank full. I start my car and it shows 1/2 full. First corner, or hard take off I do, the gauge goes down (normal), but it stays down, and reads around 1/4 full. I find the only real time the gauge is accurate is on start up after it has rested for a while. I've gone on the highway many times with what seems to be an "empty tank" when in fact i have a several gallons left. Meh the cars are old, my whole fuel system is orginal except for one line to the carburator.

I saw somebody at a car show, I think it was a corvette, and they had a pin whole camera mounted inside the fuel tank. Mind you he had cameras everywhere, even the engine compartment, and no rear view mirror either, just a camera in the trunk key hole. He had all the cameras wired into one flip up monitor, reallllllly cool.


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http://i58.photobucket.com/albums/g249/sleeper_05/pic4.jpg
1968 Chevrolet Nova
All Original (Stock)

Yes, my sending unit came from classic industries and when I get this solved I'll be glad to share the info. Thanks guys.

Skip

Do you have the ground wire from the dash harness connected to the speedometer cluster?

Do you have the ground wire from the dash harness connected to the speedometer cluster?

Greetings,

I had the same problem and this is what fixed it for me.

Jason

Do you have the ground wire from the dash harness connected to the speedometer cluster?
i am pretty much an idiot when it comes to the electical aspect. can you give a little more information on this solution. I replaced my sending unit and then filled up my tank and it will only read 1/4 of a tank.

Yes,what 49wood said, tell us more about this "ground wire to the speedometer cluster" senario. Please elaborate.

Skip :)

I just saw this in a Chevelle site:

http://www.camaros.net/forums/showthread.php?t=73968&highlight=fuel+ribbon

It's a similiar problem I had with my original sending unit in my 73 but on mine I soldered the different parts together.

I would also do a search in this site for some more troubleshooting tips.

If the wire from the gauge to the sending unit is disconnected it will read past full and if shorted to ground read empty. If you want to check the accuracy of it you can put an inline resistor on the wire from the gauge to a good ground and with a 45 ohm resistor the gauge should read about 1/2 tank, with a 90 ohms a full tank, with a 22 ohm 1/4 tank and with a 67 ohm 3/4 of a tank.

Jim