85 300D anaroid valve

I have some questions concerning the valve/switch that is connected to the vacuum line coming from the intake manifold to the anaroid valve on the injection pump. Where does it get its power from/what activates the switch? What happens if it is bypassed? Thanks for any info.

[Larry Delor]

Hi
I would say that it gets its power by the vacuum created inside of the intake. and if you disconnect it you will loose power. I believe it is for fuel enrichment for when your steppin' on it.

hope this helps

-Larry

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03/83 300D
07/73 280

Yes, but where does the electrical input come from, that opens the changeover valve, to allow vacuum to reach the anaroid valve? Thanks again for any replies.

If you are talking about the boost pressure line, the solenoid is part of the over-boost protection system.It never gets vacuum, diesels don't create manifold vacuum (no throttle plate). The solenoid is normally open. When the pressure switch on the intake manifold is grounded(by too much boost pressure)the solenoid is energized and prevents the pressure from reaching the aneroid compensator. If the switch is by-passed, you have no over-boost protection.
Regards,
Randy D.

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W.R.Durrance
ASE Master Tech
Mercedes Tech 19 Years

[Larry Delor]

I have absolutely no idea what I was thinking when I posted the above reply, (I had this nagging feeling that something didn't 'sound' right, but I couldn't put my finger on it) after reading Randy's reply, it all fell into place and I must say that I am now wearing a large egg on my face.

-Larry

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03/83 300D
07/73 280

Thanks, Randy, for your help. This clears up my confused brain, and now it all makes sense. This is a great sight.