Earths are good! I think it maybe the fuel lifter pump! Defo something's not right as I had it starting then cutting out as soon as even with easy startYou may need to go back to basics and check everything. You haven’t knocked the cable off the stop solenoid on the injection pump? Is power definitely getting to the glow plugs?
Other things I can think of is check your getting fuel to the injectors, your battery hasn’t gone too flat, your earths are in good condition? If none of this helps I think your in the realm of someone needing to look at it in the flesh.
Yeh the stop solenoid clicks so that's working I'm thinking it's a fuel issue and the lifter seems quite spongy even when it's been primedsounds like a fuel issue, does stop solenoid click if you have ignition on and remove/refit the wire on the solenoid,does it bleed up