YOU HAVE TO PUT ON A SCAN TOOL ... also put a fuel pressure gauge on the fuel rail on the intake manifold area.. pressure key on eng off 60-65PSI.. if the pressure is below 55psi hard start or no start.. replacing a fuel pump when it was failed then you should replace that fuel pump relay old truck electrical issues....REPLACE THE FUEL FILTER... your MAF has oil on it well the engine has sludge in it and the crankcase ventilation system is not working . spray MAF cleaner on it and inspect the hoses on the top of the engine ..replace the PCV VALVE.... IF THE GAS TANK DROPS BELOW 1/4 OF FUEL THEN FUEL PUMPS DIE.