I recently changed the plugs in my car and I pulled the fuel rails and the injectors off just to make more room for my hands. I noticed that there is a valve stem like fitting that looks like an airhose would hook up to. After you put the rails and injectors back in do you have to charge the rails or anything else after?

 

no, that is a port for testing fuel pressure at the rail.

 

it is a schrader valve for testing fuel pressure and also to remove all fuel pressure from your fuel rail before removing.