1) See if you are getting spark
My favorite way is a shot of starting fluid, easier than pulling a plug and all that jazz
2) See if you are getting fuel
a) Fuses first
b) Then relays, switch it out with one with the same part number with something that you know works
c) Check fuel filter. I've seen engines that won't start with clogged fuel filters
d) Fuel pump have a buddy sit by the fuel tank and listen to see if he can hear the fuel pump turn on when you turn the key to on but not turning it over.
3) Then there is the all the odd ball stuff like holding the pedal to the floor and turning it over if the tps sensor is bad.
The 1996-1998 ZJ's used a completely different PCM, both in function and appearance. I haven't heard about similar problems with those, if there were those directions wouldn't apply other than in a very general sense.
mine died on me a few months back - computer said it was the distributer, but after replacing it and everything I could think of, why not the crank sensor? yeah - that did the trick. Ive learned never to trust the computer LOL
I cant remember what codes it gave me, id have to go back outside and check it - I had my dad helping me, which turned out to be more money for me in the long run LOL - after that my husband had enough and had it towed to my mechanic lol