How does the 603 shut off mechanism work?
 

How does the 603 shut off mechanism work? What happens when the key is turned off, what is connected to where? TIA

ooops sorry... should be in the DIESEL section...

Moves the fuel rack to a zero delivery position.
The vacuum diaphragm does the exact same thing.

You need to install a vacuum switch valve in the ignition circuit to stop the engine with the key, the engine stops when vacuum is routed to the shutoff of the injection pump.

In 123, 124 etc the vacuum lines actually are connected to a valve on the ignition lock housing, in your W140 that bit is missing. Use any generic vacuum solenoid valve for this purpose.

ok, so in effect... I have to apply/supply vacuum to the solenoid to shut off the engine. Copy that! :) thanks!