I believe you have a Manual shutoff somewhere near the middle of the Valve Cover on the Linkages. The Paper Sticker that identifies it is often missing.

If you cannot figure out where it is reach over and grab the very last Linkage Rod that goes down to the Fuel Injection Pump Throttle Lever.
Pull up or push down on it. I believe pushing down on the Linkage will shut it off and allow you to see where the Manual Shutoff Lever is.

The Vacuum Line from the Vacuum Shutoff at the Fuel Injection Pump goes to another Vacuum Valve mounted on the Steering Colum Lock. Sometimes that Valve is plugged or no good and some times the Hose connectors are not good.

From there is another Vacuum Line that eventually connects to some Y connector and the main Vacuum Line. The line connectors or the Y connectors can also be bad.

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84 300D, 82 Volvo 244Gl Diesel