first of all check whethr there is a current flow to the heater plugs when you turn the ignition to ON position. if its k den no heater problems takin into account dat ur heater plugs are new..
next time try to kick da diesel pum (the round button like thing on top of the diesel fuel filter). kick means not wit ur leg! ha ha. press it around 5 to 10 times until its becomes hard to press. den try starting. coz if there is an air leak in the fuel filter gasket, (O Ring) den there will not be any pressure n diesel will go back to the tank from the filter. so u have to keep on starting to bring back that fuel to fill the filter and then the pump.
if all else fails, then after u start the vehicle n run for around 10 to 15mins or after a small drive, remove the hose that goes from the intake manifold to the head tappet cover. if u see white smoke or even smoke for that matter, that means u have a compression leak. this means ur engine is worn. replace the piston rings. this will solve ur probs.. u might be lucky if ur piston sleeves arent bruised.. cz if u find lines on dem, den u have to resleeve them as well which will cost u 5000 to 8000 for the sleeves only. this happens if u still run the vehicle with a compression leak, without changing the piston rings..
wel, best of luck!!