Like it has been said timing belt and tensioner are imperative, need to be somebody who knows or the pump timing might be off a little or a lot and will be [censored] also you will need a locking tool for the pump to keep it on time, there is more about it but it will take a lot more writing. Glow plugs, you might have or not the fast ones, maybe they were changed already, for the last 20 years only the slow ones are used with the turbos. The injection pump might be leaking at the front seal, might be the seal it could be the bushing, if the glow plugs are warming up and doesn't start, clean the surroundings of the fuel line from the filter and fill the pump with fresh diesel, filter it as best as you can, put the fitting back and crank the engine it should start. If it has been sitting for a long time the diesel might have bacteria so drain it and change the filter. Injectors go out of tolerance after about 60k miles, something to remember. There is more if you want to, if you decide to throw it away because it seems too much trouble please let me know where, I'll help you taking it out of your hands.
