Water in the Fuel Tank???

The other day, my wife and I were out driving the '70 GT when the engine started to to run very rough. And the same time, I noticed that the fuel gauge was showing near empty. I stopped at a gas station and filled it up just to get home. After leaving the gas station it begin to run very smooth again as it had before. I surmised from all that that there could be water in the tank from an accumulation of condensation over a period of time and that as the fuel level dropped in the tank to near empty, that the fuel pick up was getting into some of that water. Does any of that make sense? I was also very glad to see that the tank has a drain plug in it which I haven't opened yet as I still have a full tank. Appreciate any experience with anything similar.

Cheers - Dennis

any substantial amount of water will settle to the sump no matter how much fuel is in there unless its constantly slushing around. Lets hear it for the drain plug! AMEN. IF water is only problem, a quick drain will fix it. If there is alot of sediment, that another job entirely.
Rob

most tanks do not have a drain plug. saddly.

It could be that your sender is off calibration (which is normal) and you were just about out of gas.
Draining the tank however with a plug is easy.

Water always goes to the bottom of the tank. You're just as likely for it to go through the system with a full tank as an empty one. I'd rule out water in the gas for the fuel pump sucking air when gas sloshed away from the pickup.

With a drain plug on the tank, it would be an easy check. I wish I had a drain plug on my gas tank.

I'll back the low fuel option, rather than water. But rather than hassle with draining the tank, a can of "dry gas" in a full tank should take care of any water.