Where does this vacuum line go?
 

hello again gents,

here is the problem on my 83 300d. the vacuum bleed valve (the white one on the injector pump for regulating vacuum) has a vacuum line unhooked that i don't know where it goes. ok here's what I know: the line off of the top of the white bleed valve goes to the brake booster line, auto transmission, and vacuum block on the top of the valve cover. now here's where i get lost. the bottom 3 way vacuum connector comes off of the bottom of the white bleed valve, goes to the vacuum block on top of the valve cover, and finally, into the grommet on the fire wall where everything goes under the dash in my passenger compartment. This black vacuum line, while going into the firewall grommet, doesn't connect to anything on the other side. where does this hook up to and what is it for?????

Sounds like the vent line that should be open to atmosphere. Have to see a pic to be 100% sure.

here is the line (red arrow)
 

i attached the diagram with an arrow. hope it is the vent!

here it is