What's the standard answer with a diesel - If you've got compression and fuel it will run.
If you've got diesel at the glow plugs then it looks like thumbs up for the fuel side of things - Pressure pump doing it's job along with - if there is one - lift pump in the tank.
Contraversally, have you in turn cracked off the fuel lines past the pressure pump to make sure it's pressurising as it should. I'm wondering if air is getting into the diesel as it's being pushed/pulled up to the pump - any signs of leaking anywhere?
Second contraversal pointer, have you tried a squirt with Easy Start in the air feed pipe after the air filter prior to air going into the inlet? I know alot of peeps would never use Easy Start because of diesels becoming addicted to it, but I've done it twice now with my Kia Sedona 2.9 when it's been a non runner. Easy Start got it fired up and seemed to run fine after - until the second fail.
On the first occasion the car stood outside my house as a non starter for 6 months. Initially thought head gasket but couldn't get the bottom crank shaft bolt undone (story of my life) and was getting ready to scrap it. As a last resort, and on the advice of an old school mechanic, gave it a good squirt as the engine was being turned and it fired up and after a few coughs and spluts, ran OK.