1979 f150 the fuel gauge is a 1/4 off. When I fill it up in the neck, the gauge reads 3/4 full. Anybody ever had this problem? Previous owner replaced tank last year with a new one.

 

You have to bend the float rod down I'm thinking. Easy fix if the tank is down.

 

Thanks. I wish I had known of gauge problem when tank was removed to replace filler neck hose.

 

I had tha same fuel gauge issue with the brown truck.

When I put a new ground lead from cab to block, the problem went away

The gauge measures resistance to ground, so it needs a good source of ground

 

Nowe that sounds easy to fix. Thank you

 

Hope it works for you

 

Any update, OP?

 

Thanks for asking. I had forgotten about this post. I don't think I had ever filled the tank full. I have a filling issue. I have never put over 10 gallons at time in the truck. It takes approximately 30 minutes to pump 10 gallons. If I drove it regularly I would be crazy by now. After pumping 10 gallons the gauge reads above full. After 100 miles it reads 1/4 full. I never have driven it beyond that before filling it up. It has a new filler neck hose and vent tube.

 

Thank you. That helps build a data base.

 

I suppose it can be run anywhere but where did you run your wire?

 

Firewall to cylinder head

There was a small gauge wire, factory installed, that ran from the rear of the drivers side head to the firewall. Both mounting bolts were fairly good size, so I replaced the wire with a battery cable from O'Reilly

before attaching the cable to the firewall, I sanded it down to bare metal.

 

I also ran grounds from block to the cab and frame. I wanted to get ahead of electrical issues. Plus i fear electrolysis on my aluminum radiator.