How can I rig up a manual shut-off switch?
 

I need to shut off my 300TD engine without opening the hood.

Any suggestions on how to set up a vacuum switch to shut off the IP when the ignition switch is turned off? All the factory solenoids, switches and relays were removed prior to getting the engine. And, I don't want to buy $$$MB parts if I can avoid it.

Thanks

You don't necessarily have to use vacuum. A mechanical means might be easier. Possibly a Bowden cable or even a pull cord. Are you using vacuum for anythng else?

You need a shut off valve on the IP and a shut off switch connected to the key switch.

I have a working shut off valve i will let you have for $40. The switch is ~20 bucks from Fastlane. You will also need two gaskets for the valve. PM me if you want it.

Run a tube to the cabin and suck on it. :D

My thought exactly. I've done it myself but never bothered running it into the cabin, just ran it out under the hood at the cowl.

I would not rely on vacuum for this. If you had vacuum, why would you use the shutoff? I'd use a cable like for a lawnmower/aircraft throttle. $6 at autozone. Pimp it out, run it to the dash, screw a pool ball on the handle, #3 or 5 for visibility, or #2 cause if you're using it, you've probably gone #2.

If you can't repair something as basic, simple and necessary as the vacuum shutoff for these cars then you need to sell it and buy a Yaris. {with warranty}
Please.......:rolleyes:

http://i29.photobucket.com/albums/c2...mjustsayin.jpg

I completely agree. The vacuum shutoff is about as simple as it gets.

1. Vac source to a valve. (key switch or your own valve, use an aquarium valve if you want. :D)
2. Valve opens and lets vacuum down second tube to shutoff
3. When vacuum reaches shutoff it turns off engine.

Not exactly complicated.

I had to do something similar with my G class.

The shutoff valve is at the rear, bottom area of the injection pump. If you apply vac to the valve, the engine will stop.

Easiest way to control the vacuum is to use a vacuum solenoid. The previous suggestion of sucking on a vacuum tube might work, but it didn't for me (I tried!).

I went to wrecker and found a vacuum solenoid from a VW fox; they seemed to be the easiest to pull out. Then it was just a matter of connecting the vacuum solenoid to a switch and power, as well as vacuum.

Why not? It worked fine for MB since the mid 70s.

70's to mid 90's all across the world. If you have any vacuum source, there really isn't a good reason to abandon such a simple working design.

MB made some of their systems so simple. I just don't understand why people want to sometimes irreversibly (or reversible, but not in a simple manner) hack them up when they break as a cheap fix, and then make them complex.

Because most American folk are hardheaded....
 

I think it's because ol' Henry Ford didn't do it that way.....and wtf do those metric lovin' Europeans know.......

It's an American attitude, initially I thought it was just in the folks who served in WWII.....anti Nazi thinkin'.....but I have observed that the resistance to learn anything European is ingrained far deeper in our "American" society....

I think that the Germans began to use "vacuum" because it was a "free" energy source that was available and unused in Gassers......

Bottom line, the vacuum system works well...if maintained...!! And it continues to work if you disconnect the battery.....these older Benzez that we discuss here are pretty much 100% mechanical, and don't need electricity to run.....if I wanted to....I could remove the battery in my 190D 5 speed and just park on hills......

From a previous thread, the OP is installing a 617 engine in a truck. So some of the simple and basic components (like an ignition switch with a vacuum valve) don't exist.

A little perspective:

There is a switched power source already on the truck and little vacuum solenoids used for emission equipment are common on almost every g@sser.

Refer to the thread title. Devote special attention to the word "manual."

Use a button or momentary toggle switch.

One of my cars came with a pull cable (like a choke cable) that was installed under the dash, and ran to the STOP lever area. A small hole had been drilled in the stop lever, and the cable run through the hole and fastened.

When you needed to stop the car, you pulled the cable handle and remotely pulled the STOP lever. It worked fine.

However, the next owner got the vacuum stop fixed and so I removed the cable.

For something of a junker, you can go this route and save on the necessary vaccum parts. Isn't the vacuum stop mechanism the part on the injection pump where if you don't replace it properly, the engine goes to full revs and blows up?

Sometimes a simple fix is the best value, in the context of the particular car involved and the economics of the situation.

Ken 300D

I bet it wouldn't blow up before you could vice grip the fuel line.

I found an electric-triggered vacuum valve on ebay. Thanks for the help.

They still sell Generic Manual Choke Cables with a plastic Knob on them. Hooking it to the manual shutoff lever would not be difficult but you would need to make a bracket/frame to hold the outer portion of the cable to keep it from moving. And you need something on the inside to mount the Cable also.

A manual shutoff inside would be handy to have if other less mechanically inclined people drive your car. If you Vacuum Shutoff malfunctions they may not remember or be able to lift the hood, locate the Manual Shutoff and shut the engine off.

Boy, what a tough crowd. Whether a person has the ingrained "anti-european" attitude or not, we all start out NOT knowing many things about these cars and their systems. Let' face it, German engineering is different - for better or for worse, and there is a learning curve. We all pretty much have to start at the bottom of that curve, so let's not be too hard on others who are just getting started - we were all there once too.

Lets not be too quick to pre-judge, because, as this thread illustrates, a lot of the time that premature judgement is based on our own pre-concieved notions that may or may not be correct...

I have the shifter knob from a peterbuilt w/a 16 speed tranny w/ 2 vac switches on it.



big trucks use air pressure for a lot of stuff. 1/2 of the switches on the dash are prolly for air. meaning a pneumatic toggle switch. you could prolly get one @ any truck shop. maybe a bad one(leaker) would work fine on vac vs. pressure.

I have the shifter knob from a peterbuilt w/a 16 speed tranny w/ 2 air switches on it.
looks cool, but dont mess w/ them switches while driving.

The engine can run for quite some time with the fuel supply cut off.

Stick with the original design and fix it when it breaks.


It's also fun to watch the expression on the face of my American gear head friends when I tell them I've fixed an engine oil leak at the ignition switch!

This has been debated and tested here before. It can't. Once the fuel line is clamped the pump can't suck any more fuel.

I think he means, it'll start burning oil, and now you've got unmetered fuel coming in. Then it explodes.

That is false. I HAVE done it and the engine will idle for at least 30 seconds with fuel flow to the lift pump completely blocked.

Thank you. If anyone thinks I'm so stupid, that I need to buy a new car, they may want to review the build I linked to for my truck. It took a couple of days to locate an electrical over vacuum switch that I knew would work. All Mercedes hoses and wiring were gone when I bought the engine.

I'm a master auto-body mechanic, and I'm now training to be a machinist.

Roy

30 seconds at idle equates to what at WOT, though?
Next time I replace my feed line, I'll have to check it out.

Of course, there's always the phone book over the turbo intake method too.

I don't think anyone is saying you're stupid.
Some may have misunderstood your intentions, but I think rcounts is saying that ignorance is different than stupidity.

It certainly is.

My main point was don't be too quick to "jump" on someone assuming that they are either ignorant OR stupid. Doing so can end up making YOU look foolish when it turns out that their question is due to neither ignorance NOR stupidity - but rather due to their situation being other than what you assumed it to be...

As is too often the case, that which is crystal clear to the writer was not adequately communicated to the reading audience. Full disclosure of the nature of the task in the original post would have prevented a truckload of confusion.

.

I wonder if the inlet side of a windshield washer pump would provide
enough vacuum to shut the engine off ?

Or for that matter control the door locks ?

Hmmm, me smell a project.

Easy remote door locks.

:jester:

.

So I could install a valve on the incoming feul line and stop the engine by starving it of fuel. Clever.

Clever, perhaps, but hardly original.