I have a 93 accord that has a problem with the gas guage, when you filler up, it doesnt go all the way up. Is there any way to fix the guage?

 

Might be some high internal resistance on that circuit causing it not to go all the way up even though the lever is at full inside the tank.

A voltage drop would only tell you the truth.

 

Could be that the float was damaged at some point and is physically not rising completely with the fuel level.

 

Barnacles! When I replaced the fuel pump and tank on my 88 CRX it looked like it was covered with rusty barnacles on the inside of the tank and the pump.

Also the fuel sending unit was rusty. Its made of wire wrapped on a rectangular post. When the float rises and falls an electrical contact rubs on the wrapped wire. Its works kinda like a dimmer switch. So if the wire is rusty or corroded it shows up on your gas gauge strange. You need to clean off the fuel sending unit. I disassembled mine and soaked it in phosphoric acid.

 

I will swap out the fuel sending unit and see if it fixes the issue. Thanks for suggestions ya'll.