Just cleaning up the replacement rail that has my Nismo injectors in it, when I removed the covers over the top of the injectors 4 had an extra metal shim/washer (see below) and 2 had the black plastic that seats into the cap.

 

I haven't used these before but I have been told that they have been flow tested but I don't want to put them in after the plenum pull and then find out they might not work. :no:

 

I suppose the obvious thing to do would be to use the injector caps that are currently working fine with my standard injectors, but I'm curious now as to what these little bu$$ers do? :lol:

Anyone?

you need to use both parts...the rubber insert and the small metal plate.

 

The metal plate keeps the injector firmly pushed down, without it the injector would have too much play as the rubber alone isn´t as resitant as the metal plate. The rubber insert with the hole in the center is basically there to give the top little "piston rod" part of the injector room to move up and down.....if that makes any sense

 

:)

Thanks Maz, that makes sense.

 

H