1978 300D engine cuttoff problem

Well I bought the car, only has a few problems.

The biggest problem is you have to open the hood and hit the fuel cutoff switch in order to turn the engine off.

The guy who sold me the car said it was vacum related.

I stopped at Crown Mecedes and the service advisor said yea he knew how to fix it but did not have the parts, I would have to order them.

He said something about a vacum cuttof valve?

Anybody know about this or how I should fix it or where I should look for it. I have been to several sites and cant find it, maybee he told me the incorrect part name trying to make me get it from the dealership.

Other than that it runs good, going for oil change tomorow.

OK I took it to Lee Buck/Mercedes dealership for oil changed. I had a list of things I needed them to check.

Turns out the the glow plugs are shot, so I have to get a new set of those.

The vacum pump was bad, also missing several vacum hoses, the brake booster is leaking and the vacum cuttof value broken.

Having major service done due to 189,000 miles on the vehicle. They are going to adjust the vales and hydrolic lifters, replace all the fluids severice the transmission, tune up the engine, replace the belts. All of this for about 2,200 dollars.

Hoepully when they are done inspecting the car they want find anything else. Turns out the person who sold me the car did not have it serviced for 2 entire years.

Also they did not have any parts for the 300D in the 78 year. Turns out I have the oldest running 300D in my area.

After all this I still need a paint job, I can do the upholstery myself, dad use to run a shop and I stll have the equipment.

Frankly, an MB dealer is not the best choice to work on a 1978 car -- they're really not that qualified. You'd be much better off finding an independent in your area. Parts are readily available for your car, and for far less money than that dealer will charge you.

As far as the vacuum related parts are concerned, these cars run a lot of accessories off vacuum, as in vacuum operated door locks, gas flap lock, trunk lock, etc. The 3 biggest things to go out in these cars are the pump, which ca n be rebuilt , the switch on the end of the ignition switch under the dash (if this goes out, you may start to notice a small oil drip fromunda the dash-it's motor oil) and the drivers door lock vacuum element. If u want to trace the leaks inevitable in this car, get someone who enjoys cigars and have them start blowing smoke into the larger vacuum ports. Wherever u see smoke, u got leaks. Buy 3 meters of part # 000-158-88-35 plastic vacuum line from a dealer, as well as 1 meter of 117-997-09-82 rubber hose and 1 meter of 615-476-03-26 leak off line. This last part is the rubber line that runs from injector to injector. This is the next thing that will rot and give u diesel fuel smell. Spend a couple hours cutting and replacing all the plastic vacuum line u can find under the hood.

thanks for the part numbers, went and got them a bit ago. The car is in much beter shape but still starts a little hard have to pump the gas pedal. Alos has a neet deisel smell to it on cutoff, something to get use to. I am going to have to replace the speakers. the guy that had it before me put a cd player in it that pushes 50 whatts per channedl, and of course it overloaded the factory speakers.

I just drove it a while ago the only thing that bothers me is the interior lights are not very bright, I still have to replace the air compressor and fix the temperature control system, and get a paint job, but when I am done it is going to be a very nice restored car.

still looking for good seats.

Justt got your reply. The instrument bulbs are probably 2 watt. you can replace them with part number 000000-000853 which are 5 watt. As for the speakers, I replaced the whole schmear in my 77 280se with wiring and everything. I got the 5" Sony speakers for the deck shelf behind the rear seat and then cut in circles at the bottom front of the front doors and mounted another pair 1/2 covered by the map pockets. When I installed the in dash cd player, i just tapped into the antenna harness and bypassed the fader switch in the center console. If you have a rocker switch in the center of the dash for your antenna, it's designed to put it 1/2 way up, all the way up and all the way down.
One other thing I thought of on these older cars is the seal that goes all the way around the rear window. If it gets really dry, you'll see leakage onto the rear parcel shelf, or into the trunk.