If the pcm, crank shaft sensor, both coils, distrubator cap and rotor, tps have on 2001 Dodge Ram Van 2500

all been replaced what else could cause it not to get fire?

I've learned that the p.c.m has to be flashed before installation.And I assume the battery is in top shape: never over look the battery when having this kind of a problem .Have it load tested.Since so many things have been replaced I would also go back and check over my work to be sure that something is not connected wrong or left loose or disconnected.