if you're getting spark then the injectors are probably firing too, since they're both controlled by the ECM. you can verify for sure with a noid tester though, autozone leases them out
you need to check fuel pressure the next time it happens
Usually if the ballast resister goes bad, it will run when the key is in the "start" position but die otherwise.
What are the conditions of the vacuum lines? (specifically the vacuum circuits going to the fuel pressure regulator and the MAP sensor). How about the head to body ground strap? Replacing the vacuum lines and eliminating the unnecessary ones, replacing the head to body ground and opening up the mounting holes on the crankshaft sensor all showed individual improvements this summer on the 1990 with 200K miles.
It went from cranking for about 30 seconds straight down to 10 or so. Replacing the cam chain dropped it to 5 or 6
The camchain is another thing - how many miles are on this Jeep? There was 18 degrees of slack in the cam chain by the time it made its way to the distributor. I'm sure that threw it off quite a bit.
It's the little things on these Renix Jeeps! Previous owner of it replaced ALL sensors on the engine. Why? It idled at 1200RPM. Turns out the throttle return spring was broken.
I have replaced all sensors i have added multiple grounds to all points. The cps is getting .8 at cranking. Idles too low actually.
When it starts it only cranks for maybe 5 seconds.
So it did it again yesterday and today. Getting hot spark and injectors are pulsing.
It didnt prime to the 30ish psi at first but im not sure if that was air in the pressure tester or if it was accurate. I purged the tester and it came up to propper psi. But it also started soon after that.
Im going to go ahead and put in a new fuel pump. Not looking forward to that as i just filled the tank...