I have a 92 4.0L YJ that has totally baffled me. Well about 4 days ago I lost all fuel pressure to the fuel rail. So I dropped the tank and I found out that the PO had bent the skid plate, deforming the gas tank. So his solution was to get a new sending unit and bend it at a 45 degree angle so that the pickup screen was touching the top of the tank. And in doing so the bracing on the sending unit cut the rubber fuel hose coming from the fuel pump. So I fixed the hose, skid plate, and sending unit and everything was good for about an hour. Then HELL started.
So an hour later I have fuel but now I have no spark. I have 12v going into the coil but nothing coming out. So being the genius that I am I replaced the coil, rotor, cap, spark plug wires, spark plugs, and throttle position sensor. After all this still no spark, so I pulled every fuse/relay in the block next to the battery and noticed that that they were corroded. So I cleaned all of them then replaced them, STILL no spark. After a dozen or more attempts to start I magically have spark.
Now 4 days later I magically have no spark or fuel when I come to a red light. I can hear the fuel pump when I first turn on the key. Any ideas guys?