vacuum actuator for all W124 D / 201 D
If the engine does not stop after turning the ignition key immediately, there are two main reasons:
a) the hose to the vacuum actuator
b) the vacuum actuator itself
If the hose is not porous or cracked and if you suck on the hose to the engine and the engine still does not turn off, the vacuum actuator is defective.
The exchange is simple: remove the connection hose, remove the two fixing screws, unmount vacuum actuator, mount new vacuum actuator, assemble fixing screws, mount hose - ready.