There are two washers in the injectors.
There is a thick ish copper one, that sits around the end of the wider bit of the injector.
AND, much more importantly there is a wee crinkly one that sits arouns the very end of the injector - these, so i am rewliably told by several people, MUST be replaced of the injectors are removed - they are crushed when you fit the injectors and once crushed they are no good to re-use, as they take away heat from the tips of the injectors. If there aint a good thermal contact, the injector tips will burn away and overheat.
If you need spare injectors, I have some for the 12/19J... And POS, from what I gathered I would suggest you pop some new crinkle washers in them!