Was working on the 79 240d with my son last evening and got into a little bit of troubleshooting the non-functioning vacuum system. When we took ownership of the car the vacuum line for the locking system was disconnected under the hood with a plug in the vacuum tee. Pulling a vacuum on the disconnected line showed a definite leak. Since we were doing other work in the trunk anyway, I decided to start with the trunk lock.
The trunk lock was only releasing with the key (turn all the way counter clockwise and depress the button) which I knew was incorrect. NOTE: it wasn't just that the lock was toggled into the lock position, the key was always required no matter what. Examining the vacuum pod I saw that one of the lines was disconnected. A test of both sides of the pod with the Mityvac showed it to be good. I swapped the lines on the pod and now the source vacuum line under the hood holds a vacuum and the trunk lock works without the key as it should. (Although I haven't tried all modes of operation yet.) The car also shuts down immediately as it should in the current configuration. The bad news is that the fuel filler door lock is also engaged all of the time. Also, none of the door locks respond at all. I'm wondering if the fuel filler pod lines have also been swapped around incorrectly? Each pod has 2 lines to it. (One to lock, one to unlock, right?) What is the yellow/green line's purpose in relation to the yellow/red line? Anyone have a schematic that would help clarify? ...Kevin 87 300TD 284k mi (also with non-functioning vacuum locks) 79 240D 151k mi
