First I couldn't get my 1980 300SD to start, now it won't stop.

When you turn it off, it continues to run, and I have to hit the manual shutoff under the hood.

I just put a starter on it, could it be that I missed something in that area? What controls the shutoff? How do I stop it? (strange problem to have, I think).

Any help would be appreciated.

Usually on these diesels when they do not shut off it is due to a vacuum leak or a failure, of some sort, of the vacuum system. The ignition switch has vacuum routed to it and when the key is turned off it activates this part of the system and the vacuum shuts of the fuel supply to the injector pump. Perhaps you broke a vacuum line in the replacement, these lines become terribly brittle over time, or one became dislodged. A large leak can keep components from working properly. If this non stop problem was sudden and directly after you changed the starter, I would trace and inspect all vacuum lines in the area you worked in and perhaps the intire engine compartment. There are a few threads on this problem if you need more information. Good luck.

Rick

Check this thread it may help: http://www.peachparts.com/shopforum/showthread.php?threadid=17816

Rick

Thanks. I'll try these things (if I can just find those things that are talked about in the thread...)

If you can't find some of the components I'm sure some one will help you out on the locations if you poet which they are. Good luck.

Rick

Gee whiz. Since I didn't know what controlled the shutoff, (vacuum, electric, etc.) I had no idea what to look for. As soon as I knew I was looking for a vacuum problem, I opened the hood and it was obvious - a line off near the front of the engine.

I wish they were all this simple. Thanks.

You're very welcome. I enjoy giving back information when I can; I was fortunate enough to have others share theirs with me.

Rick