Hey everyone, my Mercedes recently started idling high and becoming difficult to shut off without closing the intake valve under the hood. I figured it was a throttle linkage adjustment but was wrong. It eventually started smoking more and more, blue smoke, then when driving would smoke black. I took it to a shop where they spent TWO weeks trying to figure out what was wrong. They thought it was a problem with the injectors but couldn't know for sure until they checked the injection pump. I guess they said they needed a special bent wrench to take it apart and check it out. After a while they noticed the injection pump had no oil in it. So they filled it up and once they did the engine began to idle even higher.

What do you all think happened? What should I do at this point? It is currently parked in my garage, not safe to drive. I have seen kits to replace the diaphragm in the vacuum deal. Think that would solve it or is it something else? How bad can I expect the damage to be to an injection pump that ran dry? Would replacing that diaphragm be enough to get her purring again?

Thanks for any feedback.

Diaphragm in the back of the pump (governor) went bad or the line to the rear of the pump itself is either cracked or loose.

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
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So if the governor went bad is this something I can replace? Do you know where I could find a replacement part?

I have not tried to start the car since getting it back from the shop. They recommended I had it towed home, since the engine was running away and smoking bad.

I took some pictures tonight but they are too big to upload. I noticed the hose connected to the top of the IP to the rear wasn't screwed on. I screwed it back on but haven't tried cranking it yet. I imagine the guys at the shop took that off while diagnosing the source of the problem. I doubt that was the original source of the problem. I'll try and start her tomorrow with that now screwed on and see if it changes anything.

Any suggestions as far as pinpointing the issue and finding replacement parts?

As Mike D said and or the shaft that is on that housing.

Governor Diaphragm Test
http://www.peachparts.com/shopforum/diesel-discussion/313733-74-240d-grey-smoke-questions.html

Once the Engine is running low pressure in the intake manifold will increase the fuel (remember you have a butterfly valve in the intake). A leak in the Pneumatic Governor Diaphragm decreases the pressure on the Manifold side of the Diaphragm and causes increased fuel.

Another source of black smoke is if the Vacuum Pump Diaphragm ruptures and allows Oil to get up into the intake manifold.

What are the symptoms of a bad IP Governor Diaphragm? Has Symptoms, Cost of Diaphragm, description of how governor works.
http://www.peachparts.com/shopforum/vintage-mercedes/223548-what-symptoms-bad-ip-governor-diaphragm.html

Concerning the Oil in the Fuel Injection Pump. All you can do is fill it properly and see if there is issues (back in the 1970s we used to fill them with 40wt Oil).

The elements are lubed mostly by the Diesel Fuel so there is a good chance they are OK.
It is the Tappets, Rollers, Cam and ball bearings that would suffer from loss of Oil.

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84 300D, 82 Volvo 244Gl Diesel

I know where to find a vacuum pump diaphragm but not sure where to find a governor diaphragm. Anyone have any suggestions?