sounds like you might have a ground issue possibly. this same thing happened to my brothers car a few days ago, what we did is we took a set of jumper cables, clipped one end of the negative jumper cable to the negative battery post (with terminal on) and the other end of the negative jumper cable to the engine. left the positives disconnected. fired right up. the original ground cable was bad. replaced the negetive cable and all is working now.
97 Grand Cherokee 5.2 V8 - 242 swap - everything else stock atm