I found a black vacuum line that comes out of the little white plastic box on the top rear of the injection pump. (I think it's the shift modulator).

The other end is near a rubber fitting coming out of the firewall. That fitting has an open on it.

I wasn't sure if a black (tranny?) line should be going inside the car. Any help?

BTW,it's my 85 300D.

Mr. BILL

90 300SE
85 300D
84 300SD (sold)

The black vacuum line is a vent line and should not be plugged. Leave it open.
Bill Lewallen Lexington,Ky.

Thanks Bill!