truck cranks but wont attempt to fire

Well here's my issue if anyone has any input. I drove it last Saturday a pretty good distance, then multiple stops on the way back, at one point it may have cranked a little longer then normal to fire, but nothing too bad, then Sunday morning it refused to even try to fire, 50psi fuel pressure, and spark at a plug, took plug out to check spark again and it fired right up on 7 cylinders, put plug in and started it a few times and it was fine, took it on a short test ride to a sheetz a few blocks away, stopped, got gas, on the way home stopped at a stop sign, as soon as I touched the gas she died, no sputter, just instantly died, so far I've changed crankshaft position sensor (wow), distriputor cap and rotor, and a 20 amp circuit breaker under my fuse box on the inner fender that a wire had came loose from, sorry about the length of the post but I'm trying to give what information I can, If anyone has any input it would be greatly appreciated as I'm going on a week without my truck which I need to carry my tools for work, also the truck does burn oil, which I'm pretty sure is the plenum pan gasket problem if that can have any affect, thanks in advance for your help