It would roll over and intermittent spark at the coil, but wouldn't start. Changed module, changed coil, nothing! Got another distributor, and it fired right up, was about to set the timing, and it died. Now no spark at all?

is the check engine light on. it sounds like a bad sensor crankshaft positioning sensor or camshaft positioning sensor will cause it not to start.

I doubt the other electrical problems are connected with the no spark problem. The coil gets a ground signal from the computer which involves the ignition module and pickup coil in the bottom of the distributor.
Those components would need to be tested.

There are several pieces to the puzzle.
You would need to verify the coil has battery voltage with the key switch on. Then there is an ignition module that controls spark timing, a pickup coil in the distributor, and so on.
To be able to troubleshoot the system, you would need a book, preferably a shop manual, to get the wiring diagrams and procedures.

Re-check the basics . Does the distributor rotor rotate while cranking?Note: Distributer cap must be removed. Does the vehicle have enough available spark to plugs? Do we have enough fuel pressure 30-35psi min.? With a 12volt test lamp
check for power to fuel injector while cranking. one wire should
remain lit and the other one should blink.
NO ROTOR ROTATION = worn distributor gear,or timing belt failure.
NO SPARK= bad module,coil,no voltage to coil,or faulty PCM
RELAY.

I’m happy to assist further over the phone at https://www.6ya.com/expert/richard_9a19ee73dfa4686a

Check for injector pulse if no pulse with no spark check ignition module in distributor or crank sensor.

If all the coils are giving spark now,then you moat likely have gas fouled plugs now,so change them out with new ones,all 8 of them.If you do not have spark on all plug wires,pull the timing belt cover,and align the cam shaft and the cam,to see if the belt has jumped.If It hasn`t,replace the crankshaft sensor.

check crank position sensor if it has one, check all fuses and relays, check all connections for good connections

could be the pick up coil inside the distributor which would basically be the distiriubtor if you have not changed that at this point

Check for spark at a plug first. If none then its either the coil or ignition module. The module is located under the coil.

i had a friend with the same problem replace the Distributor the 4.3's are known for distributor rusting up on the in side