My 87 4.0 XJ is cranking, but won't start. I sprayed ether in the air filter, and it started up for a second or two, so I replaced both the filter and the pump (probably a little overkill), and now I've got pressure on the fuel rail, but it's still not starting. Before it went out, I'd been having trouble with it stalling when I was going from a stop, and it would also miss occasionally when I was accelerating hard. The morning it died, it started initially, but then it stalled when I put it in reverse it stalled (it is the manual, but I was super careful), and then wouldn't start. There is gas in the tank, I'm pretty sure there aren't any obstructions in the line, and I don't know what else it could be. I'm planning on just taking it into a mechanic if no one has any ideas.

 

TPS, IAC or bad/ clogged injectors. My guess. Good Luck!!

 

search injector pulse

 

I just went through this with my 96 XJ, so I don't know how much this will apply to you.

I was in the middle of the desert when my XJ just shut off. It would crank, but wouldn't catch. A quick check of all the fuses revealed that the fuse to the autoshutdown (ASD) relay was blown. Replacing and cranking would pop the fuse again. No spark to the distributor, but good fuel pressure. At this point, there were four possible component problems:

1. ASD relay bad
2. Crank position sensor (CPS) bad
3. Pick up coil bad
4. Ignition coil bad

All items relatively easy to change...if you happen to have them. I didn't, so I had to leave my Jeep in the desert for a week, catch a ride to town and back after buying all the components.

Did #1 above, but it didn't fix it. I was in the middle of #2 when a buddy happened to see a burnt wire right above where a plastic wire loom ended. Opening up the loom, we saw two exposed wires that were rubbing against each other where 4" of wire insulation had cracked & fell off. I used duct tape to individually isolate & insulate them, and the Jeep fired right up. The wires went to the front pre-cat O2 sensor.

Moral of the story: Check both O2 sensors (front & back) and their wires as far up as you can go prior to spending the money. This is apparently a common occurrence. If they are good, check the above components IN THE ABOVE ORDER. Check your fuses. Replace popped fuses and start unplugging components (in the above order) until the fuse(s) stops popping. That will probably be the bad component. Good luck!