I've got a 1983 300D mercedes with approximately 230k on it that has an idling/smoking problem(smoking is a bad habit). I normally run the car on B100 homebrew, but have been lazy lately and been running it on straight dino for about the last 2 tanks. Ever since then the car has been idling alot harder and smoking like hell. I am not sure if its my vacuum system or what it is but it's slowly becoming a pestilence. I must note that the smoke has kind of a grey-ish tint to it(a little more white than black). Any suggestions? I know it does need a valve adjustment.

I would do the valve adjustment, a diesel purge and might even get the injectors rebuilt.

I am still on the very steep part of the learning curve here, but from what I have gathered, exhaust smoke will often (not always) result from inefficient combustion of diesel.

So, valve adjustment, attention to injectors (with pop-testing/rebuilding if indicated), and attention to injection timing often are suggested here as procedures to address excessive smoke.

Good luck.

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1982 300cd, 140k miles

The greyish white smoke is unburned diesel fuel.

A valve adjustment won't hurt but it's most likely that you have some problem with your injectors.

They aren't properly "atomizing" the fuel so it doesn't fully combust. Basically, the injectors are producing less than ideal conditions for efficient combustion.

Some say that injectors will "pee" instead of mist leading to this problem.

I haven't ever messed with injection pump timing on my W123s so I don't know what to tell you about that.

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1993 W124 300D
-297K on the clock as I type this.

I would do an Italian tune up. Then maybe adjust the alda.
Then a valve adjustment & diesel purge.

Danny

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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If you know the car needs a valve adjustment, then I would start there.

Burning home made biodiesel hmmm, did you wash it? Any chance that some gylcerol got in there? the BD should have cleaned the injectors and fuel system. Hows the acceleration?

does a hard idle = rough idle

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Closing the store
Benzbonz.biz on your smart phone or tablet.

Try adjusting the rack damper. My '83 would smoke when idling roughly (only when hot), and a 10 minute adjustment solved the problem.

Thanks for all the replies. I vaguely remember when I purchased the car, the guy that I bought it from said there were new injectors in, but they needed some timing adjustment or something to that extent. Does anyone have any links of where you can find that online?

Timing and injectors. Rack dampener is a bandaid solution.

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Perfect...Any online how-to's?

Scroll up to the very top of the page and put the Cursor/Pointer over the Black "Resources" Button and select "DIY Links".

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84 300D, 82 Volvo 244Gl Diesel

my 92 300D just started smoking and rough idle after getting fuel at an unfamiliar station. I put some diesel conditioner in, and its stopped for the most part. I think there was water in the fuel, or it was a poorer grade fuel than what was advertised. Hopefully it hasn't damaged anything.

Normally bad fuel is survivable but the treament to fix it depends on how much Fuel and what was in the Fuel.

It is possible to get bad fuel from any place. But in genaral a place where a lot of Big Rig Truck go is safer because if they get a load of bad fuel there the Truckers are going to get on the Radio and tell everyone that can hear not to get Fuel there and that Staion is going to use thousands of dollars from people not buying fuel there. I hate the high flow rate of pumps designed to fill a 200 gallon tank as fast as possible but it it better then getting stuck on the road somewhere.

So take extra to keep you tank filled at stations you frequent that have good fuel or hit the stations that favor trucks.

I go to one that way back in 1975 Truckers said always had clean Fuel. That particular station has a lot of commercial accounts (for gasoline also) from local buainesses. They also have the smaller Diesel Nozzles and normal flow Pumps with Diesel.

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84 300D, 82 Volvo 244Gl Diesel

fresh fuel filters wouldn't be a bad idea right about now, plus some spares to keep with the car if you haven't already got your road kit sorted.

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1991 300D

I would start with filters, and check out your injectors if the problem persists.