Hello everyone hope you all had a great summer and having a good fall so far.

A new issue arose with my 1978 240D with only the passenger front and rear locks not locking using the drivers master door lock. They will unlock if for example they are manually locked with engine running but both doors will not lock with either engine running and pushing down on drivers door lock or with engine off using key in lock cylinder in drivers door. There were a few loose vacuum connections underneath the passenger floor mat but those have been fixed with no change.

Engine shuts off almost immediately after turning ignition off so I’m not thinking there is a leak anywhere.

Point or note is when engine is turned off and i go to lock pass door using key it locks but with some springy resistance.