4.0L straight 6, manual fuel injection

ok, so it started with an intermittent miss, then turned into a dead cylinder. had plugs, wires, distributor cap, rotor and coil replaced. smoothed it out for a while, then the intermittent miss came back. now, it doesnt want to start. cranks forever before it fires. seems like it is starved for fuel, so i am figuring this whole ongoing issue could have been fuel pump related. as i am no cherokee specialist, i figured you guys' input would be nice on this matter.

and just to clarify, it is not throwing any injector codes or anything, already been checked. fuel filter was just recently changed, throttle linkage was recently tightened, so that narrows things down a bit too.

 

Being an 01, ya gotta be leery of the 0331 head. It has an inherently weak wall between cylinder 3 and 4. But! It really doesn't sound like thats the problem. I would suggest the o2 sensor/s. You had mentioned how it sounds starved for fuel, which can be called running dead lean. This is when it starts pulling in a lot of air but also chugs/bucks/stumbles like the fuel is being cut out. Get it on a good diagnostics machine (with a mechanic good enough to know what he's looking for) and start looking over sensor functions.

 

Try priming the fuel rail by turning the key to "on", waiting 5 seconds, then back to "off". Might have to repeat once more. Then try starting it.

 

I am evidently an idiot, because its a '91, not an '01. How I made it 10 years newer is beyond me....