Purpose of plastic injector cap?

[Jesda]

Does the brown plastic cap on the nozzle of the fuel injector actually do anything?

[Q45tech]

Shapes the spray cone, probably more important at idle and cruise, than at WOT.

[Q45denver]

On the early version, I think it is there mainly to protect the needle tip.
Modified by Q45denver at 5:20 PM 6/15/2007

[Q45tech]

Protect from what.............gerbles in the runners..................years ago the oem came with a clear plastic slip off to protect the brown plastic shaper.

REMEMBER the idle and cruise fuel psi is dropped from 43 to 34 psi so the as designed standard spray pattern [43.4 psi] will be less robust and need shaping.

[Raxephon]

Shapes the spray cone...

Isn't there already a metal diffuser, thats part of the tip of the injector itself and not a slip on cover, for that?

Or am I thinking of other injectors Nissan used from the same era?

[Q45denver]

[QUOTE=Q45tech]Protect from what.............gerbles in the runners..................years ago the oem came with a clear plastic slip off to protect the brown plastic shaper.

Clumsy mechanics/owners/shippers. The needles break off suprisingly easy when out of the car.

[Q45tech]

I have carried 2 brand new injectors in oem boxes in my personal Q trunk tool kit for almost 10 years.....................never can tell when you have to swap an injector on the side of the road at night.

Part of my logic that if you have it, it never fails.

[Black stallion]

Also to help keep the lower o-ring from slipping off and keep any excess fuel from sitting on the injector tip (later design) correct?