Sooner or later you will need to replace/recondition the injectors. A common problem is that 1 or more of them may 'weld' themselves to the alloy head they sit in.
If they break them trying to get them out (which is easily done apparently) then that's big bucks. Head has to come off and they have to heat the head up very slowly to very hot to remove the broken bit. Then the head has to be brought back to room temperature just as slowly to prevent it warping.
By the time you have had the head skimmed, injectors, valves, valve springs and guides replaced with anything else that needs doing, most find it's an uneconomical repair - send it for scrap if the van's an old one.