This is the front VSV on the valve cover of my 1987 4Runner. See the open metal pipe...should that have a vacuum line connected to it, or is it missing the black cap thingy? I looked for photos online (and at some vacuum diagrams) but can't figure it out for sure. Thanks.

 

I think neither. My guess is a breather/filter.

 

Jim is correct. It IS a "black cap thingy" so to speak. A little filter.