I have a 79 300td, no egr. The 3/2 valve is there to allow the car to remain in 2nd gear if if the throttle is backed off, from what i understand. I put a brand new one on and i still have no/intermittent vacuum. I isolated the (used) vcv i put on, and it seems it has a major vacuum leak, so i assume that is the source of my leak.

That said, when the throttle is closed, should the cam that contacts the 3/2 valve's allow it's piston to be fully extended (so that the 3/2 valve is totally open?). Experimenting with the adjustable throttle control rod, there seems to be a finely tuned position where the vacuum operates correctly--which seems to be when the valve is partially closed. However, this might all just be a function of intermittent supply from the vcv.

Thanks!

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Mike
Vancouver, BC
'79 300td 60k miles!
import from Japan