If you can get the engine to shut down with the MityVac then that vacuum shutoff switch is functioning. There is a vacuum leak somewhere that you'll need to track down.

An alternative if you don't have the time to immediately troubleshoot the leak but still want to drive the car is to disconnect the brown vacuum line from the key cylinder under the dash and hook it up to your MityVac in the passenger compartment. When you want to shut down, turn the key and then manually hit your MityVac and the motor will stop. Kinda hokie but it looks better than having to pop the hood each time you stop and want to kill the motor.

Ultimately, you will want to spend time tracking down that leak.

.....Dan

I had about 30 minutes to play with the vacuum this afternoon, and isolated the problem to the door locking vacuum. I unhooked the yellow tubes, and plugged off the source tube feeding them, and then when I shut the car off, it died rather quickly!When I have more time, I will continue to track down where the leak is in the door lock system, but for now, it is nice to know the car with die when I turn the key off. Any idea on my glow plug question?
thanks,
Jim

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1979 Mercedes 240D (Sold to a neighbor last year,now I have room for a new one,looking for a 300D this time)
1980 Mercedes 240D(bought for a parts car, but I have fun driving it!)

my 83 300d would only shut off if I held the key in the lock position for a few seconds, found out it was the rear pass door unlock circuit. Put in a new lock vac pod and it works like new.

__________________
'83 240D 264k on 100% biodiesel/ 31mpg
83 300D 217K the $800 gem
'82 300D 267K the new WVO project car finished and driving for free
International tractor B275 on B100
Ford 555 backhoe on B100
Sargent 25 ton Rough Terrain crane on B50

Jim,
You certainly seem very capable in your troubleshooting. Makes things much more enjoyable, doesn't it?
Right after I got my 240D I also had the shutoff problem, and it turned out to be the trunk vacuum element. You can trace from lines under driver's carpet, then over to under passenger carpet if it heads over that way. There will be 2 "circuits" under the driver's carpet: one set to rear driver's side door, and another "circuit" over to the passenger side, which is the 2 doors over there, the fuel door vac and the trunk vac element. You will see......
Have fun. I would love having 2 of these to compare each other to......

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

If I do enough searches and then do enough reading, I can be very resouceful, I just need to be pointed in the right direction!(lol) Plenty information on this site, if I can just find it! Very knowledgeable people reside here, and very helpful. That's why I try to return the favor, when someone even "greener" than me asks a question, that I somehow know the answer to!

__________________
1979 Mercedes 240D (Sold to a neighbor last year,now I have room for a new one,looking for a 300D this time)
1980 Mercedes 240D(bought for a parts car, but I have fun driving it!)

If you like to tinker with stuff and save money, you can repair the door lock pods with a scrap of rubber glove and the adhesive used for repair of wet suits. I did one of mine with just the adhesive... Steve

Seems that vacuum elements are the ones that go bad in the door lock system. The vac lines under the carpets and in the doors normally stay intact since it has no moving parts. But due to the up/down action on each element, eventually the rubber diaphram tear and leak. So, I suggest honing in on the elements right away.

I found that patching of the diaphram with a piece of rubber or balloon to be a very temporary fix... does not last long imho . Save yourself time and just get a new element if you find the element to be bad. They're not that expensive especially after a $300 deal.

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the sooner you start... the sooner you'll get done If it ain't broke, don't fix it.. Its always simpler to tell the truth...
2007 Honda Accord EX
2007 Honda Accord SE V6
96 C220
97 Explorer - Found Another Home
2000 Honda Accord V6 - Found Another Home
85 300D - Found Another Home
84 300D - Found Another Home
80 300TD - Found Another Home
Previous cars:
96 Caravan
87 Camry
84 Cressida
82 Vanagon
80 Fiesta
78 Nova
Ford Cortina
Opel Kadet
68 Kombi
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