whenever i turn my key to turn the engine off, the engine just keeps running so i have to go under the hood and manually cut it off with the "STOP" lever. why is this happening?

thanks

Most likely a vaccum leak. You didnt specify year or model but generaly when you turn the switch to STOP you send a vaccum signal to the back of the injection pump that cuts the fuel. Look on the back of the pump for a brown vac tube and make sure its hooked up. If it is, then pull it off and apply vac to the port on the IP. It should hold vac. If it doesnt, you need a new diaphragm. Next check for vac on the brown tube.

sorry, is a 1985 300D...ill try to find the brown vac line, thanks

Remember, these are just some of the first things to test. The vac leak could potentially be anywhere in the system. If you have other vacuum-related problems, it's probably a clue as to where the leak is. There's lots of info. on how to test the system if you do a search. Diesel Giant also has a pictorial on it; if you haven't seen that, I suggest you check out www.dieselgiant.com.

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Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

after reading this, I tried the red manual stop on my 240D (1981), it slows down, but will not stop.

do I need sometype of adjustment to the linkage?

bob 1981 240d

Yes, your linkage is not adjusted correctly...you should be able to stop it with the lever...sometimes you have to push hard but if it doesn't stop it means the length of the rods are not adjusted properly and the linkage it is hitting the stop before the fuel cutoff is completed.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

The thing about the stop is that its not a "hard" stop. The idle screw is actualy spring loaded at the tip. You need to push the lever hard enough to hit the stop and then compress the pin. If the pin is rusted it may not work and you wont be able to use the lever for shut down till you free it. The other possibility is that your idle is turned up so high that even compressing the tip of the screw all the way doesnt force the rack closed. Check that idle stop screw and one way or the toher youll find you probkem.