Injector o ring question

Yes that's a different cylinder which has no leaks. The one that's black inside is the one that has no o ring or graphite here is the pic

 

Here another angle hope it's a better pic I just cleaned the injector and it was coated with soot

 

What say you on the injector cup most likely issue?

 

Just an update cup on cylinder 5 was bad I pressure tested it and it was blowing air through it. Took the head off had it pressure tested confirmed cup on 5 was bad. Cost me 650$ to do pressure test and 6 new cups

 

Bought gasket set online for 210$ including all injector o rings got head bolts for 165$ check valve was bad 130$ new cups+ test 650$