Pull out the 6 easiest glow plugs and turn it over for 20 - 30 seconds then let the starter cool for a few minutes and do it again until you get fuel mist coming out of the glow plug holes.
fso: fuel shut off solenoid.
By unscrewing it, the flow will be on regardless of power supply. if the engine starts and want to shut it off just screw it back in with key in off position of pinch return line to stop flow. the solenoid stops flow out the ip through the return line. This is why clear line aids, if you can see the fuel flowing through then you know it is working.
Ok. Know what it is, not familiar with the term dsl. I checked power to it, will try that. Might run supply and return hoses into a fuel can and try that too.