I lost track here a bit as I really have never read the theory of operation of the valve. I have neutered every one that got in my way; making the car run good. They were designed only to take the fuel away in decel. Basically it bypasses the airflow meter.

No US model used any such devise so I have never seen a wiring diagram. Its vacuum controlled, with the vacuum coming from an electricallyt controlled switch over valve. I don't know who does the control but it should only open when in decel. Decel is defined as closed throttle, high rpms. From the engines stand point there is never a time for this valve. So bypassing it is an appropriate test mechanism. If the car exhibits the same problem with it blocked then its not part of the problem.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician