Tweaked Fuel Sending Unit

[pacman88]

Its causing my gauges needle to move up and down while driving. I filled up two days ago, and know (70 miles later) the gauge reads 11/16's (between 5/8's and 3/4's) If thats the case, my car is getting something like 13-14 miles/gal. Thats definitely not right. I had the O2 sensor fixed and working 6months back, so I know that can't be the reason. There is no visable leak, and can't smell raw fuel (around the injectors a little, but thats normal[?]). So, I know its the sending unit, but to be sure, how can I test it? Its made bot my fuel gauges to vary while driving.

[pacman88]

I checked the OHMS as stated in the FSM and it read 24-25 OHMS. Its a little low; the FSM says its suppose to be 27.7-34.3 OHMS. What to do?