Removed all injectors (as per manual) - one being somewhat loose and attributed to the whole unit being loosened when the bleeder nut was loosened on injector 1. Had all tested at
diesel specialists (showed the spray pattern etc). 2 of the 3 injectors had poor patterns and were considered "sticky". They showed signs of burn/overheating and needles were replaced and injectors renovated.
Cost $200AU.
Hope this is of help to other cruisers.