'83 240D - Loss of Engine Power After 3/2 Valve Replacement

[Atoz]

Hello to everyone... first post here.

I recently acquired an '83 240D with a manual 4-speed (270K miles) as a hobby restoration project. The car starts right up and generally drives well. One issue that I wanted to tackle right away was the vacuum leak that was affecting the door locks. Testing the system, I found that all the parts of the locking system were good, as well as the vacuum pump (24 mmHg). I traced the leak to the 3/2 valve on top of the engine, and got a new valve to replace the worn out one.

I replaced the valve and re-connected the lines just as they had been before (photo attached). The car started right up, idled as it should, and the locks worked great. However...


the car now has a top speed of about 15 miles per hour. Just no power whatsoever. Unplugging the vacuum line from the 3/2 valve brings back the power, but I lose the locking function again. Obviously, if I then cap that disconnected line, the locks come back, and I lose power again. I don't really know what is causing the loss of power. I guess I'm looking for suggestions on a good place to start to diagnose the issue. It's my first foray into the MB universe, so I'm a bit of a noob.


Thank you in advance for any guidance.