My car has a rough idle and lays a beautiful cloud of black smoke when accelerating hard. I have had this car for about 8 years, it has 240K on it, and I get about 27 to 30 mpg. I have replaced most of the injectors, rebuilt the head, had the timing checked, replaced the fuel filters very recently. I have also replaced, over the years, almost all the vacuum lines and the engine mounts.The problems have been slowly getting worse. I recently took it to a respected independent MB mechanic and he diagnosed that the injection pump needs a rebuild. However he gave me a price tag of $2500 for the rebuild (sent out) and a $650 remove and replace fee. Ouch. His suggestion is to ignore the issues and drive the car as is. Honestly, I love this car and hate leaving that black smoke and having the whole car vibrate at idle. I like keeping in tip top shape.

Questions:
1. Can anyone recommend a source for a rebuilt injector pump?
2. Can I do this job myself? It seems to need specialized timing equipment I don't have (I don't believe the older 300D drip timing technique works on this car). Is there a way around that, or timing equipment I could buy?

 

FI, I've been running B99 biodiesel for past 8 years, although recently it has been B20. I think the ports are going to be pretty clean. Thank you for the two links, I didn't find them in my search. I will use one of them.

I don't think it is the head as the symptoms are variable, sometimes it worse than other times and after my rebuild of the head about 60K ago, the current symptoms were still present (though less than now). I also don't think it is the pistons as I don't loose any oil between changes (240K miles - that's bloody amazing!) Does my logic work?

Can anyone recommend Adsit Company or German Star for rebuilt parts? Any personal experience with either company would be appreciated.

 

"it has 240K on it, and I get about 27 to 30 mpg"

If you are still getting the same Fuel Milage as you did when you bought the Car it is likely that the Black Smoke is not being caused by too much Fuel being injected into the Engine.

You have not said if the Black Smoke smelled like Oil burning or Fuel.

Also since the Engine has been blowing Black Smoke have you noticed any difference in Oil Consumption?

If this year and model has a Turbocharger if the Seal on the Turbine end of the Turbo Leaks the burning Oil can cause dark smoke.

If for some reason the EGR or what ever your Engine has to recirculate the Exhaust Gas is open when it is not supposed to be that can cause smoke.

In general when Fuel Injection Pumps wear out they do not give you excessive Fuel.

So I think for the Fuel Injection Pump to put out excessive Fuel something would have had to happen to what limits the Fuel Rack inside of the Fuel Injection Pump.

 

I have replaced the injection pump and car runs much better. Smoother, rough idle gone. No more black smoke at hard acceleration (diesel9112- no oil burning or oil loss). However, trying to be smart, I tried to install the new pump with the same settings as the old one about 12 degrees TDC. Bad idea, can't get the timing right. This weekend I am pulling it out and resetting it again. (Much quicker second time ....?) setting the timing without the electronic equipment seems very tricky. Suggestions? Can you do it by sound? Smooth idle? Last week I had my local independent shop do and it cost $220! Ouch, I really don't want to do that again. Thoughts appreciated.

 

What degrees your Fuel Injection pump is supposed to be timed to should be on one of the Emission Sticker.

It is ususally 14.5-15 degrees After Top Dead Center of the compression Stroke.

You have a Port on the side of the Fuel Injection Pump Governor that uses a 17mm Wrench to remove it and you can buy a Fuel Injection Pump Timing/Locking Pin.
The Timing/Locking Pin locks the Fuel Injection Pump Camshaft in one position so it does not move aroungd while you are installing the Fuel Injection Pump.
There is several places to buy it but on eBay the last time I looked it was about $37.

I will look for the Mercedes Tool Number and come back and edit the Post.
Fuel Injection Pump Timing/Locking Pin
Added Mercedes [part # 601-589-05-21-00

The Timing Locking Pin plugs into the is the same place that the Mercedes A&B Light and RIV Timing set-up plugs into. So using the Timing Locking Pin is similar to using the other timing Tools but I am guessing it is not as accurate.
However, I have none of those more expensive tools to compare it with.


The pic is of the Tool