Start with the simple stuff. Replace the inline and regular fuel filter............................ Turn the key on and pull the wire from the fuel shut off solenoid on the back side of the injection pump housing. Check if you have power there........................No power, The early machines used a start interlock relay that could have failed. The later machines have a diode which also could have failed. To tell what setup you have look at the instrument panel. Is the face of the panel metal with square corners or is it plastic with rounded corners?