Fuel gauge not reading correctly

[Jeff in Norcal]

When my gas tank is full, the gauge says half full. I'm thinking the sender unit is bad. Don't know where it is and my Haynes manual doesn't say. (or I'm a dope and cant find it. of course I am.) Jeep has Howell EFI but don't think that should make any difference. Any thoughts would be welcome. Thanks!

 

[7mmpoppy]

Just replaced my sending unit last week. its in your tank. mine just quit working at all. but dont know if its possible for it to just start reading wrong? reostat should work or quit i think......
be sure of what tank u have, I bought the wrong one, it fits the tank opening but is off some, thought i had a 20 gal. but only have an 18.
not a big deal, just stays full longer and e MEANS EMPTY!
hope that helps.

 

[Old Dog]

They will sometimes start reading wrong before they go out altogether, just get a new sending unit. As 7mm said it is in the tank.

 

[BrockGrimes]

Mine did that and had a bad ground at the sending unit, food for thought.

 

[Vvajk]

Mine is kind of the opposite. I'm afraid to let mine go under 1/2 tank for fear it shows more than I have. Last time I was just under 3/4 and filled it, it took 11 gallons.

 

[Jeff in Norcal]

Everyone, thanks!! 7mm Yea I think this was happening when I bought it, and it does work fine on the empty side. Just gotta keep it in the quarter full area for now....... So if it's IN the tank how the heck do I get to it?

Took it out for its first real ride this weekend. Drove 65 miles up I80 here in CA, and it was like driving a 2000 lb. squirrel! Just a hairy drive! Went to Lake Fordyce which is a real popular (tough) spot and this jeep just pounded me. Now I know why most every jeep I saw was driven by young 20 yr. olds. I'm twice that age and it wiped me out. It's gonna be trailered to the staging area next time. Noticed later that the fewer OLD 40+ guys I saw did this.

 

[BBCJ5]

I just replaced mine along with the tank today. The only way to get to it is to drop the tank... Not too heavy when if your empty...There is a lock ring that holds it in on the top of the tank. you will have to turn that ring counter-clockwise and may need to tap it with a hammer to get it freed. The ring locks in pretty tight...

 

[Jeff in Norcal]

BB, thanks for the reply. Yea dumb arse question from me. Was looking for an easier answer. Not gonna get one. lol. Drop the tank. Yep right answer! Am I? Nope. I'll just learn to live with it. (that's what jerry cans are for) Thanks again.

 

[Jeff in Norcal]

If anyone is still reading here? Bought this jeep from a guy who's a millwright and cant contact him anymore. So he made the front bumper/winch assembly and the rear swing away spare mount with a platform behind the spare. (kinda like a basket but no sides. prob for a cooler) The rear swing away has two gas can mounts, but NOT for standard jerry cans. They measure 10 inches across (L) and 5 inches extended forward (W) and mount parallel to the side of the platform. Just like all jerry cans are mounted on jeeps. Any thoughts as to what kind of gas cans he built these for?? Thanks.

 

[Vvajk]

Everyone, thanks!! 7mm Yea I think this was happening when I bought it, and it does work fine on the empty side. Just gotta keep it in the quarter full area for now....... So if it's IN the tank how the heck do I get to it?

Took it out for its first real ride this weekend. Drove 65 miles up I80 here in CA, and it was like driving a 2000 lb. squirrel! Just a hairy drive! Went to Lake Fordyce which is a real popular (tough) spot and this jeep just pounded me. Now I know why most every jeep I saw was driven by young 20 yr. olds. I'm twice that age and it wiped me out. It's gonna be trailered to the staging area next time. Noticed later that the fewer OLD 40+ guys I saw did this.

LOL I just drove 84 CJ7 400 miles last week! Straight through with two stops for gas. I'm 37 and you're right. By the time I got home I felt like I'd been hit by a train! Won't do that again.

 

[Jeff in Norcal]

V, that Jeep looks just like mine! Cool. I only did 130 miles, but the semis just blew me all over the road. The after market small steering wheel didn't help either. Never again! Thanks for the reply.

My other confusing dumb <-BAD WORD-> question? Shoulda just said 10" by 5" gas can. That's better. Duh on my part.

 

[BrockGrimes]

10x5 sounds like ammo cans, maybe smaller gas cans.
I know some people run smaller swiss, german, russian, types.

 

[Jeff in Norcal]

I'm thinking gas cans due to the way the guy has the hooks welded on. (45 degree angle) Assuming they're for a bungee or a tie down, so wouldn't really hold an ammo can right. I'll keep looking because I want to keep and use them. The P.0. did great metal work and they look good. Thanks for the ideas.

 

[7mmpoppy]

If the carriers are for cans, maybe he was using plastic gas cans. they come in all sizes.

 

[BusaDave9]

You have a plastic gas tank with a steel skid plate. I have had the same problem. When the tank was full the gauge said 3/4 tank. I took the tank down and found out the problem was the top of the tank was bowed down. I even had a bunch of mud on top of my tank. The gauge works by a float the pivots on an arm. The angle of this arm tells the gauge how much gas you have. If the top mount for this arm and sending unit is at an angle then the gauge will read low. Take down your tank and check it out.

 

[dalefan88]

mine stopped working way before i got it. i looked the other day and where the ground wire is it is rusted bad. this weekend im going to clean it up and see if it works.

 

[dslywalker]

here;s what it looks like out good time to freshen up other parts

 

[Petescj]

Mine reads empty all the time. Unfortunately this morning about 2 blocks from work it was reading correctly . Whos in charge of putting gas in that Cj anyway? :laugh:

 

[AGR377]

Mine ran out of gas last week too. I have the same situation. The PO replaced the tank. Now a full tank only reads at 1/2 a tank. On top of that when the tank gets to full, it runs out of the top of the tank. It does not come up the fill pipe. Just starts to flow down from the top of the tank.

 

[Jeff in Norcal]

Well he** glad I'm not alone. Thanks to all who responded. Ok Busa D, yea have steel skid plate on tank. Will check tomorrow if it's plastic. It's too dark now. I don't think it is btw, but will post back. 7mm yea I thought plastic also. They do fit my 1 gallon lawn mower, blower, weed whacker plastic cans pretty close. Just a little overhang. But why .............? Millwright doing way cool metal work for plastic? Makes no sense. Gotta be for another steel type of can imho.