Fuel gauge sending unit

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Fuel gauge sending unit #742420 08/03/06 09:50 PM

Anonymous

Unregistered

I replaced the fuel gauge in my '78 cj. And now I have two problems. One, it will not register FULL when the tank is full. Is there a way to callibrate the sending unit? Second, (espicially when it's damp outside) the gauge moves from half tank to beyond empty constantly. Is that due to a bad ground? Is so, what would be a better ground for the sending unit?

Thanks. That is all for now.

Re: Fuel gauge sending unit #742421 08/03/06 11:01 PM

Anonymous

Unregistered

I'd start with the grounds. Also I don't know how hard it is to remove the sending unit, but you may want to pull it and push the float all the way up to see if the gauge goes to full. If it does, and you know the tank is full, bend the rod down a bit and see if that helps.

Re: Fuel gauge sending unit #742422 08/03/06 11:20 PM

Joined: Jan 2006

Posts: 23

Marysville WA

mudslinger258 Offline

Need a Spot

If you got a full tank of gas pulling that sending unit is going to suck, unless you have a access door on the floor of you jeep (not a bad idea to do if you don't) but what he is getting at is right you need to check the grounds and the sending unit itself, and not to insault you but make sure its wired up right to if the hot and ground are backwards it will read empty or past empty when there is gas in the tank. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Re: Fuel gauge sending unit #742423 08/04/06 08:57 AM

Joined: Sep 2005

Posts: 1,087

Southeast Michigan

BobRowe

Body Damage is Cool

Re the fluctuation... check all electrical connections, including the grounds. I'd disconnect any ring terminals, file them clean, as well as their mating surfaces, and reinstall.

Re the not registering full... When I put a new sending unit in my CJ-7, it would only read 3/4 full when the tank was actually full. After about 6 or 8 weeks, it gradually started reading full. I think the float has to become a little fuel-logged if its new.

1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.

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