I have a friend with a 1993 jeep Cherokee 4.0l XJ that had it die on him on the road the other day. He got it back to his place and it would crank, but not start. The next day it started up and he took it down the road and it died again. Since then, it just cranks. I thought fuel pump at first, but you can hear it come on and there is pressure to the rail. We replaced the crank sensor, which seemed to be the next likely culprit. Nothing has changed. All vacuum lines have been checked over and any breaks or bad elbows have been replaced. There is spark and obviously air as well. I am stumped here on what to do next. I couldn't imagine it being the timing chain because that wouldn't allow him to start it again, and for other reasons. Next I am thinking about just cleaning the throttle body and checking the IAC sensor. Any help would be greatly appreciated.

 

Try this and report the results.
pour a teaspoon of gasoline directly into each combustion chamber thru the holes for the spark plugs, then try to start it. If it starts, then you have decent spark and compression. We'll progress from there.
"Renting" a free fuel pressure gauge from a parts store will tell you what the pressure of the fuel is at the rail. Test the pressure prior to anything, with the key on, while starting, and about a minute after starting/watch it drop for a minute.

 

good idea gat wxcept that number 1 and 6 are buggers to get to ngilbert875 when your friend got it started was it like it was sorta flooded? did it change gears well (auto) if so it might be the tps