I have been following an engine cranks but does not fire issue with my 50HP TLDI. I have dismantled the high pressure fuel pump & tested. Pump works fine & was clean with no corrosion. Reassembled & refitted. Checked spark & fuel. All good. Found only 3.8 volts DC at fuel pump when ignition is turned on. I would assume that the high pressure fuel pump should run when ignition is turned on. Can't access a circuit diagram to trace wiring to the source of the supply of if there is a pressure switch for the pump. Can anyone point me in the right direction? I am a HVAC tech with 50 + years behind me & have been playing & rebuilding all kinds of engines most of my life. This little Hi tech beastie won't beat me but it's got me stumped at the moment.