Starting and running troubles

I have an 87 XJ 4.0L and am having frustrating troubles keeping it running. It won't start on its own and sometimes starts with a jump. It will run for a little bit if it starts, but then it dies again. I replaced the battery and checked as many of the connections as I could easily find. Even on a full charge there is no power going to any of the accessories (usually) any ideas? Where should I start?
Thanks, AKXJ

Have you check the starter, and starter relay. Also the crank sensor is known to do this. The start is a easy fix, next time it will not start take a hammer and hit the back end of it. This will turn it over, thus the starter is shot. The crank sensor is behind the throttle body and runs down to the back of the bell housing. Unplug and replug, if it starts the sensor is bad. The relay was something that happened to me after all of the above was replaced. Towed to dealer, replaced. Good luck