Does anybody have problems with their fuel gauge not moving until they stop for a short period of time?
I have an 01 explorer sport and the fuel gauge is very iffy

 

The gas gauge is just a volt meter, and the sending unit in the tank is a variable resistor that has a different voltage drop depending on the float level. THE gauge reads zero with the key off, and should jump up to the proper level as soon as the key is turned on. If yours sticks or drops, or ...... you have a loose wire, or a broken sending unit (failed resistor) in the tank.

 

On the 2001 Sport the fuel level sensor signal does travel through the PCM on its way to the instrument cluster. I would suspect that some amount of hysteresis is provided via the PCM. If you have a scan tool it could be interesting to monitor the fuel level over the OBD-2 port and compare that with what the gauge is showing. If the PCM responds more quickly than the gauge, I suppose you'd need to pull the instrument cluster and make sure all connections are clean and tight and you could monitor the voltage from the PCM to the gauge, but if the output from the PCM is the culprit I'm not sure what options you'd have.

If the level according to the PCM matches the response of the gauge, then you're likely in the situation Steve mentioned above.

-Rod

 

I do remember gas gauge sending units screwing up due to some additive in the gas.
It happened to me and I put some Marvel Mystery oil in the gas, and it cleared up.
If you use one brand all the time, you could mix it up by using different brands.