Gas gauge calibration unit

I have a spare sending unit to work with and a variable power supply
Turn on the gauge with your 5vdc and add the 9.6 ohm resistance to the circuit. then see if you can turn the gauge all the way to the F mark. If it will not go that far, you may need to add some additional voltage. Mine worked great at 6.03VDC.
The sender should then be set to the empty position, appx 76 ohms +- 9 ohms, then if necessary turn the adjustment to put the gauge on the E mark (or just below it)

That is assuming you have a meter in good enough shape to do this with. Mine is