My fuel gauge when empty reads 1/4 tank, how can I fix this,i found out the hard way

 

Someone may have been in the tank before and used the wrong sender or bent the sender lever, possibly when changing a fuel pump.

 

There are a bunch of different reasons this could happen. Did it ever read correctly or has it always been this way? When you fill it up does it show full as expected?

If this problem is new, as anyone been in the fuel tank to do some work? If so, then as tw1234 mentioned, someone may have bent the float arm or damaged the sender. Otherwise the problem could be a short in the fuel level sender/gauge circuit.

 

When I fill it, it goes above full and empty is at 1/4,seems like it worked when I bought the car