Hey All,

So my dad calls, leaves a message asking if I could bring my tools this Easter weekend.

It seems one of his Benzes (Benzi?) will not shut off by the key. He's got an 81 and an 83 300SD. My guess is since it's nice out, it's the 81, but I left a message for him to call me back with which one of the cars it is.

But anyway, I've got my mity-vac and a set a golf tees and I'm going into this blind. Any suggestions on what to do?

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1983 Benz 240D - 263,060 (Current)
1983 Cadillac DeVille - 130,000 (Scrapped - Stupid HT4100)
1992 Dodge B350 - 150,000 (Sold)
1984 Mazda 626 - 299,997 (Scrapped)

With the engine running take the mityvac and run it to the shut off solenoid at the back of the injection pump. If a few pumps on the mityvac shuts the car off then move on down the line and check for leaks. You can also test the ignition shut off valve(this valve is located on the ignition key tumbler). If that valve isn't holding vacuum then you'll need to replace it.

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'81 300SD

Is the setup going to be similar to my 240D?

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1983 Benz 240D - 263,060 (Current)
1983 Cadillac DeVille - 130,000 (Scrapped - Stupid HT4100)
1992 Dodge B350 - 150,000 (Sold)
1984 Mazda 626 - 299,997 (Scrapped)

Usually the quickest route is to check where the last service (i.e. oil change) was done and look for a disconnected vacuum line.

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Sam

84 300SD 350K+ miles ( Blue Belle )

It will be similar in that the shot off solenoid is actuated by the same valve on the ignition tumbler that is used on a 300SD. The big difference is that your 240D's locks are running off of the same vacuum system as the shut down mechanisms, where as the 300SD locks have their own pump in the trunk.
I had a vacuum leak in one of the door locks of my 240D which was giving me a slow shut down time. I put a golf tee in the line going from the engine compartment to the door locks, and the car shut down quickly.

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'81 300SD

Ok, so what I"m reading is that I don't have to worry about finding out which door isn't working, since they are on a different system.

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1983 Benz 240D - 263,060 (Current)
1983 Cadillac DeVille - 130,000 (Scrapped - Stupid HT4100)
1992 Dodge B350 - 150,000 (Sold)
1984 Mazda 626 - 299,997 (Scrapped)

Yes, that is correct. If both your solenoid and shot off valve check out as okay, then there might be a pod in the climate control system that is failing. You can put the mityvac on the red/green line and see if it's holding vacuum.

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'81 300SD