gas gauge way off

[Highbanked Hauler]

  I dumped the tank to get rid of the old gas so with an empty tank I put in 5 gal. and the gauge never moved so I put in another 5 and the gauge went to just a hair line over quarter full. Since I have a tank half full I am thinking about pulling the sender unit and bending the float down till the gauge reads just under half full. does this sound feasible ??  

[XS29L9Bxxxxxx]

I have read this can be done with the tank still in place. I keep "testing" mine, looking for empty. I think it is actually accurate 

[John_Kunkel]

Before you go bending the float wire, be sure the gauge reads full with the float topped out...this can be done outside the tank.

Also, the float might be full or partially full of gas...can't be checked without removing the sender.

[Highbanked Hauler]

Before you go bending the float wire, be sure the gauge reads full with the float topped out...this can be done outside the tank.

Also, the float might be full or partially full of gas...can't be checked without removing the sender.

   to check the gauge for full just pull the wire off the sender. correct???

[doctor4766]

Before you go bending the float wire, be sure the gauge reads full with the float topped out...this can be done outside the tank.

Also, the float might be full or partially full of gas...can't be checked without removing the sender.

My "float" had a pin hole in it and that made it more of a "sink"
Replaced it with a plastic float and the gauge was alot more accurate

[Highbanked Hauler]

its very possible it could be the float. Its a S.S. unit from some vender. My gauge never read more than 3/4 full when the car was new but it was close on the bottom end as I put 18 gal. in it a few times.

[doctor4766]

Still better than showing more than you actually have though......

[Highbanked Hauler]

Still better than showing more than you actually have though......

yep thats for sure, worst case is figure gallonage times distance.

[elacruze]

I went the other way. I don't care how long it takes for my gauge to come off full, but I care a LOT that it only reads empty when it's empty...so I set mine with the tank in the car and no gas in it. I bent the float until with tank empty it just barely moved the gauge, then bent it a tiny bit back to get it as close to E as possible. So now I use 1/4 tank before it comes off F, but I can be assured that when it says E it means it.

[gibber]

You can check that its not the gauge itself by getting a 10 ohm resistor from Radio Shack and disconnecting the sender wire from the sending unit, put the 10 ohm resistor in the line, and them ground it to the frame someplace. Full, the gauge requires 10 ohms resistance, 23 ohms for 1/2 tank, and 73 ohms empty.


Mark
www.thegaugedoc.com

[poppa]

Isn't there a "check" you can do? My gauge is off too. I thought a few years ago (when I had problems with it) you could take the wire off the tank sender and put it to ground and turn on the key ?

[oldcarnut]

A little info from my experience with something similar.  Just have to scroll to the relevant parts
http://www.dodgecharger.com/forum/index.php/topic,57376.0.html

[TXcharger70]

We I got tired of buying floats cause I would try to adjust to read empty and ruined two of them 3rd one was reading empty at half tank so I left it at that as long as I know that's all that matters. I look at it as an Anti-theft