Just recently bought the wife a 92 cherokee that needed a motor. I bought a motor and swapped them, both were 4.0 straight sixes. I went to fire up the new swapped in motor, and it would start and run for about a second and then quit. So first I replaced the crank position sensor. Still same problem. Cleaned up cap&rotor, put new plugs in, still same problem. So my buddy came over today and we hit it with the starting fluid, and it would stay running on ether. Thinking the fuel pump was dead, we replaced it this evening. Go to start it and hear it purr and no change. Still runs for a second then quits. Anyone got any suggestions on what to look at next?

She's getting awful antsy...

 

fuel sending unit?

 

One of my buddies is real big into the jeeps, he lives on www.jeepforum.com and www.naxja.org. they can prbly help out pretty quick. hope that helps.