Air and Fuel system questions

[RustyBolts]

This 240D W115 of mine is definately different. It's the only Diesel I've ever seen with a butterfly valve in the intake. Behind the front butterfly, there is another one (barely visible) that isn't connected to any linkages like the front one is.

You must be registered for see images attach

There is also a "Jet" at the bottom of the butterfly with a fuel line attached to it coming from the IP (far right in photo)

You must be registered for see images attach

Could someone please tell me what this is, what it's purpose is, and how it works?

 

[The Warden]

How sure are you that that's a fuel line and not a vacuum line? I seem to recall those butterfly valves having something to do with the vacuum system (and somehow trying to create an intake vacuum similar to what you see on a gas engine; the line going to the IP could be a signal line or a vacuum source line).

I'm not 100% on this, though; those butterfly valves were a feature of the early 240D's, and later 240D's and all of the 300D's didn't have anything even remotely resembling this setup...so I haven't dealt with them directly...

 

[RustyBolts]

How sure are you that that's a fuel line and not a vacuum line? I seem to recall those butterfly valves having something to do with the vacuum system (and somehow trying to create an intake vacuum similar to what you see on a gas engine; the line going to the IP could be a signal line or a vacuum source line).

I'm not 100% on this, though; those butterfly valves were a feature of the early 240D's, and later 240D's and all of the 300D's didn't have anything even remotely resembling this setup...so I haven't dealt with them directly...

Not 100%, but this one has a vacuum pump that has a seperate line into the intake manifold toward the front. The discoloration in the clear line looked like fuel to me, but I'm kinda on board with the vacuum signal to the IP. Don't know what it could be used for, but. . . this is german technology after all.

 

[Turbo OM617]

Could someone please tell me what this is, what it's purpose is, and how it works?

Read about it here: http://mercedesforum.com/forum/dies...djustment-mw-m-pumps-pyrometer-install-46097/

You must be registered for see images attach

The first butterfly is the emergency stop. The second is the throttle.

The injection pump is completely controlled by the throttle flap and intake vacuum. The accelerator pedal has no connection to the pump and there is no governor.

 

[RustyBolts]

Hey, thanks for the link! I'll give it a read in the morning, and get back to you.

 

[RustyBolts]

Wow, that's different.

 

[Turbo OM617]

Sorry, first is throttle, second emergency stop.

 

[RustyBolts]

So is it more vacuum=less fuel?

 

[Turbo OM617]

Yes.
Thats why if there is any air leak (vacuum pump diaphragm, throttle shaft, cracked/broken hose) the engine can run out of control.