Hello, I have been working on "Ben" 1983 300D Turbodiesel and have been having trouble with vacuum.

I bought the car recently and the problems at that time were the door locks and the center vents. There was a golf tee in the yellow line going into the cabin at the firewall so that the engine shut off would work.

I began working on the vacuum system and made it to the trunk and found a small pin hole in the rubber of the trunk actuator so i replaced it and at first it seemed to help. Then I modified the EGR lines by totally removing them. Then for a month I would shut down the car by pressing the STOP lever in the engine bay, but nothing was functioning properly.



Then gradually the car started acting better and would shut down and the door locks started working.

Now this week we drove to the store in town and the car shut right down and the doors locked fast and good. But when we returned to the car unlocked the doors and the car would not start. Vacuum was keeping it from starting so I locked and unlocked the doors until they would not move and the car started right up normally.

Once back home I tested vacuum at the main lines that read 21 and 20 and then the vacuum stopped working, no stop and no door locks.




Question is; why would the vacuum at first not shut the car down or work the locks and then over the space of 2 months time everything worked great until one day it works too well and will not let the car start and then after checking vacuum for two minuets not work at all again?