I've spent a lot of time tracing vacuum routing and such just to make sure everything is hooked up properly. I tested my vac control valve as per MB and it didn't provide the 385 +- 25 mbar (11.4"hg) at engine idle when warm. Raising engine RPM did nothing to change the reading.

I acquired a used VCV from a forum member who tested it before sending and I installed it this morning and I get the same behavior at idle, zilch. I have a constant -21"hg to the VCV but nothing else. With the new VCV now I can get a reading greater than 0"hg when I raise idle up to at least 1500 rpm.

Any clues, anything I've missed? This is a stock setup at this point, W140.

Thanks
Steve A

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Steve A
92 W140 OM603
97 VW Jetta TDI
90 Passat variant TDI 6 speed MT
94 Chevy K1500 6.5TD
05 E320 CDI
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