[JFlanny11]

Took my jeep off the road for 3 months to do some work on it, after those 3 months I started it up again, and the fuel sending unit doesnt work.

Can sending units rust? Reason I ask is because the tank was empty for those months, and I have a leak somewhere at the top of the tank when I fill it all the way, so oxygen could get in I am assuming.

Should I get a new tank/sending unit or wait till the new gas I keep putting in somehow effects the old sending unit and makes it start working?

Thanks

[SuB8HaVeN]

I'd check the wiring and the ground. Do you have an ohm meter to be able to see if it's sending anything to the gas gauge?

[JFlanny11]

Thanks, I very well could have hit a wire in the months i have been working on it, I'll get ahold of a meter and test it.

Do you know where the ground would be?

[CjinPA]

The ground wire from the sending unit would be under the rear drivers side of the Jeep. The ground wire comes from the top of the sending unit and goes to either the rear drivers side frame rail or rear crossmember. to check the gauge you can dissconnect the posative wire that goes to the top of the sending unit (The posative wire has a plug in it about a foot prior to where it connects to the top of the tank under the rear drivers side of the Jeep) run that wire to ground and the gas gauge should go up. Dont hold it to ground for too long or you will ruin the gas gauge. If the gauges goes to full then the gauge and wiring to the plug are good and you have four posabilities, a bad connection to the top of the sending unit, a ground problem, a bad sending unit, or a cracked float. You can mess with the ground wire to see if that solves you problem. If the ground wire is ok then you will need to drop the tank and remove the sending unit to check the float. If the float is in one piece I would replace the sending unit.
My gas guage worked prior to me rebuilding my CJ. The tank sat for a little over 2 years during the rebuild. When I was done and I started the Jeep my gas gauge no longer worked. I dropped the tank and found that the brass float in the tank had a crack in it and had filled with gas.

[JFlanny11]

thanks for the info, ill do what u said in the morning and post results

[motiv8ya]

I'm thinking this is exactly what my problem is. My CJ was off the road for a few years and now the fuel gauge doesn't work. I did all the tests listed throughout these forums and it's gotta be either a bad sending unit or bad float. The gauge passes the pink sending unit wire to ground test so that should all be good. The sending unit reads about 73ohms (empty) within acceptable resistance range, however I know the tank is full (cause I ran out of gas and just filled it) which makes me believe the float is cracked..

[motiv8ya]

Originally Posted by motiv8ya

I'm thinking this is exactly what my problem is. My CJ was off the road for a few years and now the fuel gauge doesn't work. I did all the tests listed throughout these forums and it's gotta be either a bad sending unit or bad float. The gauge passes the pink sending unit wire to ground test so that should all be good. The sending unit reads about 73ohms (empty) within acceptable resistance range, however I know the tank is full (cause I ran out of gas and just filled it) which makes me believe the float is cracked..

Replaced the float today, the gauge works

[mmerlina]

When I bought my CJ, one of the first things I did was replace the entire fuel sending unit. Reason being was that my gas gauge wasn't working and that's where I traced the problem to. As soon as I had it in my hand, the 2 metal tubes on the top that handles the gas just crumbled, so I just fixed 1 problem and avoided one down the road.

Mine still leaks when I fill it all the way. Damn jeeps.

[h2ojeep]

Make sure the frame is clean where your ground wire from the tank to the frame goes. Do that first, simple and may be an easy fix.