The float lever in your fuel sending unit may have a built up residue on it preventing the float from rising and falling properly. I believe your vehicle has an internal fuel sending unit within the fuel tank. and I believe that your access point for this fuel sending unit is from within the vehicle under the rear seat. This float lever on your fuel pump assembly can be cleaned or moved by hand (up and down) to help break up any residue that may be hindering it's movement. In this case you only need to fiddle with the float and nothing else. This information is based only on the information you gave about your fuel guage and not about your fuel flow. there is a bolt in the center and behind your back seat. remove that bolt to remove the seat. unscrew the fuel unit shield, disconnect electrical connectors & fuel lines. remove the sending units mounting screws or bolts and slowly pull the unit up and out far enough so that you can reach the float and just start playing with it to gain free movement and then re-install in reverse order.
