Help no start after dizzy replacement!!

Ok heres my prob, I have had this little vibration around 1500rpm and when I would put it in reverse it would get worse, so I found a broken motor mount, replaced it, still the same vibration. Than the other day I pulled out of the gas station and when I came to a red light it all most died then it ran fine. Went home and started to probe.
My spark plugs are good (2 months old)
My distributor shaft had some play in it
put a new reman dist in today with new dist cap and rotor button
started the jeep same dang vibration at 1500rpm
so I was looking at my O2 sensor and found the harness that has the coolant sensor and O2 sensor has melted so I unpluged the O2 sensor and started the jeep again and same fing thing, vibration around 1500rpm (the vibration is like a shutter or a small miss fire)
now I closed the hood and went to start the heep and nothing (everything works but no start
I also changed the trany fluid the other day and same thing
any rpm after 1500 it runs smooth and you can hold you foot to the floor and no hesitation runs strong
I have also replace the CPS, TPS, about 4 months ago

my Jeep specs
1996
4.0HO
auto,np231, dana 30,35


Help

Crank, no start or no crank?

cranking just fine, battery is in good shape
no start, I have not checked if I have spark going to try after work
but what i dont understand is it was running fine then all the sudden nothing

Well, post up what you find out about the spark.

When the engine is running you can pull one spark plug wire at a time while holding the RPMs at the 1500 mark to try and isolate the miss-fire. You can do the same with pulling an injector wire, you just don't want the particular cylinder to fire. If you can't locate the cylinder this way it means it is a random miss-fire.