Fuel tank gauge reads empty?????? But it's not. (1 Viewer)

[boerboel313]

Hi all, it's been awhile.
So my 84 60's fuel gauge isn't reading correctly. WTH? Even though I've installed a 38/38 weber and I can watch the fuel gauge needle fall while driving (6-8 MPG). There is a diesel swap somewhere in the future. So let me get back on track, Once the needle is in the red and I fill the tank, it's only taking 14-17 gallons.
When I start driving it falls to around the 3/4 mark.
Do I have a faulty fuel tank sensor?
How difficult is it to replace?
Should I have the tank cleaned prior?
Should I install a larger tank?
Thanks all.
Cheers

 

[Output Shaft]

It's probably the sender.
Remove the inspection cover in the back of the car, make sure the electrical contacts leading to the sender are good, remove the sender from the top of the tank and check it out. Move the lever up and down and see what the gauge in the cab does.
Official fuel capacity for the tank is 23.8 gal.

Big fuel tanks are niffty if you often travel long distances in areas devoid of gas stations. If that isn't the case, they are an expensive way to force you to put the spare tire inside the truck.
http://www.man-a-fre.com/parts_accessories/fj60longrangereplacementfueltank.htm

https://forum.ih8mud.com/threads/long-range-tank-install.860602/#post-9771201

 

[Lugal]

Mine does the same thing, and has since I bought the truck 7 years ago. I'd swap out the sender, but the screws that hold it in place are so rusted that they're stripped out. So I just reset my trip odometer every time I gas up, and fill the tank every 200 miles or so. That gives me a good buffer--the only time I've ever run out of gas was last summer, when I let it get to 260 miles, and it ran out about a mile from the gas station.

 

[IBFJ62]

I'm guessing the sweeper arm on the sending unit is sticking.

 

[Lugal]

On mine, I think that the coil is worn out near the mid-way point. Full tank, it reads full. After 60 miles, it reads about 1/2 tank. After 70-75 miles, it reads empty. Also, as it gets closer to the mid-way mark, it fluctuates more with braking/acceleration/turning than it does near full.

I seem to remember a thread here that discussed repairing the coil, but given that I can't get my sender out without surgery, it's a moot point for me.

 

[Output Shaft]

On some boats, they just use a dip stick.

 

[boerboel313]

Thanks for all the useful and the not so useful information. Lol
I may end up installing a new 38 gal tank.