1979 300td

Does anyone know what kind of vacuum my lift pump should be producing?

Thanks!

As seen below in the chart; at idle speed it is 0.1 bar of Vacuum. It does not say minimum or maximum.
You will have to convert the negative bar pressure to whatever your gauge reads in; inches of Mercury or inches of water. There are internet sites to help you with this.
Also it is assumed that when you take the Vacuum Reading that your Fuel Tank Screen and the Fuel Tank Vent are not restricted; also your Fuel Filters should be new.

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84 300D, 82 Volvo 244Gl Diesel