Well I messed around with the in-line pump today; by disconnecting the "inline pump fuel line" to the filter I was able to get fuel past the pump and then after reconnecting the fuel line I was able to get fuel to the Injection pump, she then started right up. I guess there was proble air in the lines. I ran the motor for +/- 20 Seconds and the return line discharged perhaps 2 quarts of fuel in that 20 seconds; Does that seem to be normal? Or perhaps I should look at the overflow valve? The intake line from the gas tank is 1/2", maybe that's to big?If the fuel filter is full then the lift pump must be delivering it there. If by chance the lift pump was bad it is easy to replace. You could have air in the fuel lines. Have you bled the injectors to be sure of that. Is the fuel shut down solenoid on the injection pump working correctly. If not, no fuel can get into the injection pump. On the P7100, you can disconnect the solenoid and operate the arm manually. That is an item that would have high probability. There are a few other lesser possible causes. The overflow valve on the injection pump could be stuck open and venting all the fuel back to the tank. Having sat for 3 years there could be parts in the pump that are gummed up. My bet would be check the shut down solenoid.
Charles, What is the proper amount of Fuel return per minuteThe 1/2" feed line isn't too big. No problem there. 2 quarts of fuel in 20 seconds does seem a bit high. That would be circulating 90 gallons per hour back to the tank. The pump does send excess fuel to the injectors which is used to cool them. What fuel that comes to the pump and not used is routed back to the tank via the overflow valve. You have 2 return lines in the system, one from the injectors and one from the pump which join into a single line. The issue with the overflow valve is there is a spring that gets weak and sends too much fuel back to the tank. Those valves are not horribly expensive and very easy to replace. There are also adjustable aftermarket models which you hear mixed opinions about. Below is a drawing of the valve's location.