My 1986 Pontiac Parisienne is equipped with an Olds 307 engine.
It has one port on one side of the valve,and two ports on the other.On the side that has two ports,one doesn't have a vacuum line,and that jives with the schematic of vacuum lines.
My question is this:Is that second port without a line just open or should it have a cap? Mine is open and it seems strange that the car would have a design where vacuum is being pulled through it in an open fashion.(I've found other vacuum issues with this car,bad ruber hose,bad EGR,and while the car now runs fairly smooth,it doesn't have the get up and go that it had when younger.(Neither do I!) btw,it's a maintained car with only 86k.
Thanks in advance.

 

That open port might be the exhaust of a dump valve, where any vacuum stored in that system would be relieved. There is one atop the left valve cover on my '86 and there used to be a little foam filter on it. Naturally they would dryrot and vanish. Just find a chunk of open cell foam and make a new one!

BTW, welcome to the site!