if the injectors are not receiving power it could be the resistor box yes. you should get +5v at each injector. if you don't then check the box. if the box isn't receiving power from the yellow/black wire in the harness then the problem lies elsewhere. (i.e. break in the wire). if you are low on fuel pressure, but its there, then the pump is either dying, or the filter is clogged, or both. If no fuel pressure than either the pump pooped out on ya, or the main fuel relay is being retarded and not kicking the pump on. if need be you can run a direct +12v feed to the pump and test it to see if it kicks on.