The PTU runs the Spark Plugs.. so it was not necessary to change that if you have spark. Back to basics.. Do a compression check. If compression is low, you might not be able to get it to fire. Please post what you find. Check the Ignition Timing.. should be ~15 Deg before top during crank.. Mark the Pully Marks with White fingernail polish.. so you can see it
Usually out of desperation, if all looks good, I'll open up the Intake Manifold ( some fitting ) and squirt LOTS of starting fluid into it, then close it back up.. It it stumbles.. it's a fuel issue.. Are the Fuel System Hoses Backwards?..