My car is acting up! 1993 ford explorer. help please?

I assume that it is water in the gas tank because I didn't start having problems til I filled up the other day. I put half a tank in. it rove fine at first but I stopped in at the store and when I came back out and tried to start it up again it jumped to 2000 RPM and shut itself off on me. Now that is what it doesevery timee I try to crank it up how ever when I take the intake thing that runs from the fuel injectors to the air filter off, it seems to run better, like it's actually trying on its own. Is that water in the tank? and If so I hear that putting alcohol in the tank will mix the water and the gasoline together and make it burn. Will that really work? And it is rubbing alcohol right?