Does it only do this when it's raining?
Sounds like one of the 2 gremlins of "Jeep No Go" - Fuel or Electrical. Fuel side, could be as SIMPLE as changing the fuel filter (Last time you changed it was?), And could get more complex from there. Do you have pressure at the fuel rail after it dies? Does your electric fuel pump still put out with the engine off and key on? (Can be checked at fuel rail, has a fitting with cap that looks like a "valve stem" on car tire - remove cap, depress center button - don't get gas in your eyes!).
Electrically, could mean loss of spark (many causes), some easy like crapped-out/cracked distributor cap, rotor, bad wire to distrib, and gets more complex again. Not impossible to diagnose, but will require more information.
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Wednesday, December 17th, 2008 AT 12:19 PM