help!!!!! xj no start

90 jeep Cherokee xj

4x4

4.0

auto trans







3 weeks ago I came home jeep was running great.....shut it off and it hasn't started back up



ive replaced

spark plugs

new wires

new distributer

new cap

new rotor

new crank sens.

junk yard ecu





still no start.... ive got spark and getting fuel but it just turns over and doesn't strat





ive spent a lot of money on this jeep and would like to have it running but if I cant get it going soon im going to scrap it out





can anyone help me out here? ive tried everything I can think of but it just wont start





thanks rob