I had two Chrysler cars with these symptoms. In the first case, a mechanic diagnosed it to be a fuel pump. After being $400 lighter in the wallet, the problem immediately returned. It ended up being just water condensation in the gas.
In the second case, the problem would always and only occur during a rain storm or wet weather. I ended up replacing every electrical part on the car before visiting the junkyard and geting a replacement computer. Replacing the computer solved the problem, but in retrospect I think the problem may have been that water was getting onto the electrical connecter to the computer.