So I went ahead and hit the 98 cherokee with a hard blast from the "Parts-cannon" after thread searching similar issues and thinking "oh this must be the problem"

Last year sometime the old trusty jeep took my wife and I to the grocery store and after loading up with groceries, decided not to start.

Not hearing the fuel pump priming... simple replace fuel pump----- not it
replace ignition coil---- not it
replaced crank sensor--- not it
replaced cap n rotor--- not it
replaced ignition switch--- not it
removed and cleaned up all engine grounds--- not it
checked all fuses--- not it
verified all relays are operational--- not it
verified 12v+ at PDC and cleaned up connections for good measure--- not it
bought a used matching ECU--- not it

MORE INFO>>>
if I jump the ASD relay it will not start, if I jump the ASD relay and the fuel pump relay it will fire right up and run normal.
I ohm tested the crank sensor and pin B and C ohmed at 725 or so. Replaced crank sensor again and tested before install and it tested good (per "Bleepin Jeep video") after I cranked it post new crank sensor install, I re-ohm tested new crank sensor and it tested at arough 725 ohm like the one I just replaced. WTF!!!

What would cause the crank sensor to do that after just one crank???
what is the next step??? Electrical gremlins are my nemesis.

I am really at a loss at this point and never intended the "Ole' Parts Cannon" But after thread digging it just ended up that way as my wife really misses her Jeep. Some of the parts I tried replacing aren't that big of a waste of money as they were old anyways so what ever right...

 

You should check the crank sensor for pulses while cranking. I'm not clear on how to do that but unless the PCM sees pulses, it won't trip the ASD or fuel pump relay. The ASD relay controls the ignition and the injector circuits. If you're not getting pulses, go buy a Mopar sensor and make sure the wiring to it is okay.

The crank sensor is a magnetic switch and Mopar uses a neodymium magnet whereas aftermarket ones usually don't. My new one would lift a screwdriver! The sensor operates about 1/16" from the spinning flywheel and must be spaced correctly. If the flywheel hits it, it's usually finished! My Mopar sensor had a paper spacer on it that gets torn off on the first start, but that was for my WJ with the 42re trans.

 

Mopar only on crank and cam sensors.
If you say you jump the relay and the fuel pump runs, you have a connection or wiring problem there. Not a parts problem.

 

I will figure that pulsing while cranking aspect out and thanks for the reply.

Do you know what pins on the ECU are responsible for the crank sensor? Figured I should test continuity while I'm at it.

 

Any conclusion?