Research CKS crankshaft position sensor, when it goes you'll get no power to coil. Don't get it confused with CPS camshaft position sensor, that is in the distrib.
There is a way to test the CKS, lots of info on the web about it. Pretty common problem on these old riggs. I have the 4.0 so I don't know where yours is located.
When mine went out my Jeep just died while driving then crank no start. It did not throw a code.
Have you looked for codes by turning the ignition on-off-on-off-on-off-on then wait for the CEL check engine light to flash. Have a pen ready to write the codes down. All the codes are two digit example Flash-flash-flash (pause) flash-flash-flash would be code 33. At the end of the codes it will flash a 55, that means End of codes.
If you need the codes let me know.