Fuel Gas guage not passing the half full mark

[MUSTANGJOE]

Hi everyone,

I have a small issue with my 91 GT.

Just filled up the gas today as the guage was on empty. Now the gas guage does not go past the half full mark? I filled it up to the max, it should be at full.

what do you think the problem is? Faulty sending unit?

thank u!

 

[General karthief]

Did you fill it with the usual amount of gallons that match the gauge reading when you stopped?
I'd be all shaken the back of the car hoping the little float thing was stuck. And when that didn't work I would fall to my knees shouting NNOOOOO!
Yes my neighbors think I'm crazy.
Oh, does the gauge move at all now? I think it should move a little when the key is turned off.

 

[MUSTANGJOE]

Did you fill it with the usual amount of gallons that match the gauge reading when you stopped?
I'd be all shaken the back of the car hoping the little float thing was stuck. And when that didn't work I would fall to my knees shouting NNOOOOO!
Yes my neighbors think I'm crazy.
Oh, does the gauge move at all now? I think it should move a little when the key is turned off.

Lol!

Yes it moves, I was on empty and right after I filled up I saw the guage rising but it stopped at half a tank, it did not go up all the way to full. It is definitely full to the top the gas 100%

 

[General karthief]

Have you tried shaking the back of the car?
On older car stuff we used to check the gauge by using a 9 volt battery, key off, negative to body (ground) and positive to the gauge wire, gauge sweeps to full, gauge is good, don't know if that can still apply.