Hi all

So I noticed that there is what looks like a throttle body on my 73 220d which through me off for a while because I didn't think diesels had a throttle body...........and they don't AFAIK. I later found this is part of the pneumatic governing system for the IP.


But here's my question.

There is another one on the back side where it attaches to the intake manifold that appears to just stay open all the time.....there are no springs, levers or the like to return it once opened after applying full throttle.

Is this valve supposed to always be open?
What is it's purpose?



This is the one where the intake boot from the air filter attaches which is opened and closed by linkages attached to the accelerator pedal/IP.








And here is the one on the back side that just sorta does nothing AFAIK. The arm on with the little ball fitting far left of it opens and closes the first valve......it also opens the one in question....but nothing closes it. Is something missing?

__________________
73 220D
08 997 C2S
03 Jetta wagon TDi

I too have a missing link (no link at ball socket at pic #2), what's strange it only moves the throttle valve, and when i do that it makes the engine sputter (similar to when a gas engine is running lean)

__________________
Current Garage
2008 Mercedes GL320 CDI 188k mi Repair/Work in progress
1994 S350 160k mi Garage Queen & prepping for repairs
2005 E320 CDI 203k mi Healthy & Daily Driver
1994 S350 357k mi Retried as parts car
1984 300TD 214k mi Blown OM617 Poss OM603 Swap??

Sold
1987 300SDL 200K+
1994 S320 181K mi
2008 E320 Bluetec 127k mi
1999 S420 130K mi
1980 240D 360k mi
15+ Others that has come, stay and gone

GONE, BUT NOT FORGOTTEN
1995 E320 SE 220k mi
1984 300SD 350k mi