Vacuum diagram OM 602td
 

I have a pressure operated WG on my engine. Is everything else the same on my engine except for that compared to the w126 diagram?

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I want to install a eco-meter-instrument from a gasser instrument cluster in my 190td car. Can I attach that to the vacuum signal that goes to the gearbox determining engine-load to that eco-meter? Will that then become a fuel flow meter?

There are more rogue "T"s here than I can keep track of.......

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These Diesels don't generate intake manifold vacuum like gassers do so there's no direct way to use vacuum as an indicator of load. Transmission vacuum is an approximation of load based on throttle position. If your car has a transmission vacuum amplifier (blue flying saucer thingy), the vacuum signal to the transmission is integrated with boost so it might give a better interpretation of load. I suspect what you propose is a Rube Goldberg interpretation of a throttle position sensor more than a load indicator but in general it should provide visual guidance as to how your driving style affects fuel economy.

It's a fuel flow meter only to the extent that throttle position correlates with fuel flow. Having a transmission vacuum amplifier gets you closer than a simple throttle position indicator.

Sixto
87 300D

It's a fuel flow meter only to the extent that throttle position correlates with fuel flow. Having a transmission vacuum amplifier gets you closer than a simple throttle position indicator.

Thanks for the good help. Yes, I have the blue saucer. I assume it`s operating range is between absolute 0 to 15 psi. -Like on a NA gasser.

Will the instrument operate like it does when connected to a gasser, or inversely? -is high load much or low pressure?

The economy gauge is a vacuum gauge and in a gasser it's connected to the intake manifold so it should behave the same way connected to the transmission modulator line in your car.

I don't know the operating range of the blue saucer nor how it corresponds to the gasser economy gauge. You'll have to run a graduated vacuum gauge in parallel until you learn what different economy gauge behaviors/positions mean. The economy gauge is highly damped so it won't respond as quickly as a regular vacuum gauge.

Sixto
87 300D