I had the same issue in my 99 xj
my battery was bad so I changed it.
It didn't work I cleaned the wires on the connections and replaced the connections.
Once I did that it fired right up.

 

I've done that to but still no start?

 

I'm still looking for the clockspring but I dont think my 92 has one unless your talking about the ignition switch, I tried the horn fuse still no change. thanks for the suggestion.

 

bump

 

What do you mean by "fires but won't run"?

Does it start with the key turned to START but dies once you release the key to RUN? If so, check the ballast resistor. You can simply connect the two terminals together to bypass the ballast resistor.

Does it start and run but runs rough and then maybe stalls out? That could be due to the leaky injector. How do you know one is leaky?

If your reverse lights are intermittent, it could be the neutral safety switch (NSS) on the transmission. Key in run (do not start), parking brake on (better yet, block the wheels). Put trans in reverse, check for 12v at the reverse lights. Also check ground. If no 12v, try shifting from 1-2 to park and back again a few times and check again. If you get 12v, it's more likely the NSS. Lot's of vids on how to clean it.

Let's start (no pun intended) with those.

 

First of all no it doesn't run with the key turned to start. Only cranks.

Second fuel pressure gauge went from 39 psi to about 20 25 psi and the fuel pressure sensor and fuel pump are brand new.

Now I'm getting a closer look at the spark and its intermittent it will fire on the first 2 cranks then cuts to nothing so it pops sometimes but doesn't run.

 

bump

 

bump