Maybe a tree will fall on it!

I have a 1993 Ford f-150 with duel gas tanks. When it warns up, it sputters, and dies at stops and the gas will spontaniously move from one tank to the other. We’ve changed the spark plugs/wires, battery, fuel filter, oil changed. What’s wrong with this stupid truck!! Any feed back is appreciated.

There is something wrong with the fuel control vavlve and/or switch between the two tanks.