misfire

You Jeep has one ignition coil shared by 4 cylinders with plug wires going out to each,.Under engine load the ignition system is under most pressure and the spark may want to find the easiest path to ground rather than jump across the spark plug gap. Water is a good conductor of electricity if any of the plug wires are bad or there is a crack in the insulation of the coil the spark will use the water to find a path to ground. Check the plugs, wires and coil. With the engine running get a spray bottle of water (like Windex or any household product) spray water from one place to another of the ignition system and see if the engine starts to run rough when you spray a certain plug wire or the coil area, if so you have found your problem.