Hey guys, ive been messing around trying to modify my vacuum system and cut out what i dont need. I never have understood quite as well as ive wanted to, how this system works. So if anyone knows how the system on a w124 603 works, please send me some advice. Ive attached some pics below and can take more if neccessary.

This is the engine over-boost protection I think, but someone has done something with it.
Remove those solenoids, and wire the hose directly from manifold to ALDA-valve, if you want to get rid of it.

Do you have som pictures of your intake-manifold?

Here are pics of the manifold with vacuum from the alda to the manifold. Is this setup going to rob me of power. Or should it function just fine. My worry is that the ALDA with recieve constant vacuum and cut fuel.

There is no vacuum in a diesel engine no throttle body!!! Just boost pressure the ALDA goes from idle at 0 psi and when there is boost it ad's fuel!!!

If you put a vac/boost gauge on you car it will read 0 at idle and 10-15 psi under boost! It should be the same for the ALDA line!

I ment pressure not vacuum sry. But the pressure is not going to activate the alda?

The ALDA is naturally set to take fuel/power away it only ad's fuel as boost increases!

If it did not have boost going to the ALDA it would be a very slow!

The purpose of it is to add fuel to match the boost to limit smoking at idle or when you leave a light!

Thanks for the answers to the vacuum question. I was hoping for a solution to a power loss and ive finaly found it. Ive got oil coming from the turbo. its seems to spool like crazy but not provide boost. So looks like a revamp. Thanks again guys.