Hello All Would love your advice re my 200tdi in an old 110.

Been a while since I was last on, missed the sarcasm so here I am.

Just had new pistons (Bearmach)+20thou, cylinder rebore 20thou, cam belt, water pump, all gaskets etc, valves re-ground etc, head/block skimmed. All sounds lovely and feels much smoother now. None of it was Brit-Part.

All the oil leaks have gone.. miracle.

I now have quite a large diesel leak from the second injector nearest the bulk-head. Have checked the holding plate that secures the injector, it's nice and tight. The banjo on the return fuel line bubbles slightly but I'm not tightening this up more than I already have until the spare ones arrive, already broke one and it had me off the road for 3 days.
But there is no way the banjo can account for the amount of diesel. Under revs their is a constant drip from the sump of nice clean (expensive) diesel that is running down the side of the engine. The drips are about a 2 seconds apart.

If the injector needs replacing do I need to replace them all?

Thanks.