wont start need help

my 96 neon highline has new plugs and wires and also a new pcm and coil pack and the fuel pressure is fine and all the connections and grounds are secure and in the right place but it wont start and all four cylinders are firing can somebody please help me?

thanks

it didn't start before you changed those parts???

if it didn't start, did you check timing belt?

engine trouble codes?

routing of wires to plugs correct?

i dunno- it was kinda vague ? to begin w/...