1993 Jeep Cherokee car wont start

One year ago, the pcm and the cps were replaced (mopar parts). Before and after the car seemed to take a few revolutions to start. Recently noticed vehicle starting to cut out momentarily at speeds in excess of 55 mph. This symp was what requirec the previous install of the pcm and cps. Today I replaced the dist ahd the cam pos sensor, new cap and rotor. I checked the coil (has spark), timming is correct and the fule pump and injectors are functioning. I have also inspected all breakers and fuses both inside the cabbin and the engine compartment, all appeared ok. I also check all wire / weatherpac connectons. No frays, burn thru or other visible anomolys. What have I missed. Please help ! Thanks
Martin