I need help with my 1993 Dodge D150. It has a 5.2 litre, its MPI. The motor only has 25,000 miles since rebuild. The problem I am having is I'm getting back-firing through the exhaust. I've replaced the fuel filter, cap, rotor, pick-up coil, and the coil, plugs, wires. I also have replaced the crank sensor because the truck kept dying and then wouldn't start, traced that back to the crank sensor, replaced it solved that problem, but still have the back-fire. I checked fuel pressure it should be 35 - 45 psi, I'm getting 30 which I know is a little bit low but when I pull the vacuum line on the fuel pressure regualtor, I'm getting 40 psi. Still has the back-fire. So I feel that it is not a fuel pressure problem. The truck does have a cam sensor, but I am not sure if that could be my problem or not. Any help would be greatly appreciated.