1985 Mercedes 300TD; Key Won't Turn Off Motor (1 Viewer)

[JJS]

A friend of mine has a problem with his '85 300TD where the key will not turn off the motor. Fuel continues to flow in the off position, so he has to pop the hood and use the manual fuel shut-off. Can anyone shed some light on this?

 

[Poser]

A friend of mine has a problem with his '85 300TD where the key will not turn off the motor. Fuel continues to flow in the off position, so he has to pop the hood and use the manual fuel shut-off. Can anyone shed some light on this?

Read away... <---- this is a link

 

[Chrishdj80]

In order to stop the engine running.
The diesel injection pump is moved to the stop position by a small vacuum powered actuator on top of the pump.

You probably need a new one.

When turning off check if the vacuum line on top the dieselinjection pump is sucking. If so replace the actuator.
If not look further up the chain.

I've got a couple of those OM617 300 diesel engines running and they all develop this "scary at first" problem.

 

[JJS]

Thanks for the help. I'm heading over there tonight and will pass along the info.