Hi everyone,
I have a 1980 300D non-turbo. About two weeks ago I went on a quest to get the car shifting better. I followed many different guides on this awesome website and got my clunker to shift as smooth as butter. Not long after this I started belching black smoke under heavy load or anything above 3/4 throttle. I have adjusted the valves, replaced both fuel filters, the air filter, set the pump timing via drip method, temporary plugged the egr vacuum line, ran a can of diesel purge and then finally replaced the injectors . None of this seemed to make much of a difference. Of note, when I pulled the valve off the number one injection line it seemed as if the fuel about to be squirted was much dirtier than it should have been. I had cleaned the area around the valve prior to removal to avoid contamination, but maybe it had some dirt get in there. I pulled the up until then #2 valve and found the same thing. I decided maybe it was just dirty fuel and hooked up an auxillary tank (milk jug) under the hood with good fresh diesel. I filled a new main filter with ATF and went for a drive. I drove 40 or so miles, stopping and refilling my jug. It still smokes. Anybody have any ideas where I should focus next? Thanks in advance

The mileage on the Engine would be helpful.
Does the smoke sell oily or is blueish in color?

Is it possible the Valve Stem Seals are shot?
An other timing issue would be the Timing Chain Stretch.
If the IP has an Aneroid (it changes the Fuel delivery to compensate for altitude) maybe the inlet is plugged or it is no good.
As far as you know does you IP have a Mechanical Governor.

Just info- when IPs get contaminated fuel in them it cause scoring on the plungers an barrels. Fuel leaks by the score marks and the IP will deliver less fuel. So, it is unlikely dirty fuel in that area of the IP would cause the IP to put out more fuel and cause the smoking.
However if dirt gets up to the Injectors it can sometimes damage the seats inside of the Spray Nozzle of the Injector (I think this type of problem would show up more at idle than at higher speeds).

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84 300D, 82 Volvo 244Gl Diesel

Black smoke is too much fuel..........period.

Fuel filters, valve stem seals, cam timing, timing chain elongation, mileage on the engine, and contaminated fuel are all irrelevant to this problem.

The first thing I would search for is a blockage of some type in the intake system. I could be something as benign as a rag or any type of foreign matter. Anything that restricts airflow is of primary concern.

The aneroid compensator is present to restrict fuel at higher altitudes. You haven't mentioned where you are located, but, if you're at 5000 feet, the engine will put out serious smoke if the aneroid compensator is not functioning. If you're at sea level, this cannot be your issue.

what i think brian wants to say is that the fuel to air ratio is to high,

am i right


just clarifying this for myself

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Current
2006 E320 CDI, 57K bought at 67K "Liesl"
1986 190E 2.3-16, 198K bought at 56K "Brigitta"
1987 300TD (Chuggin Along), 292K "Friedrich"
1995 E320 Wagon, 200K "Louisa"

Past
1987 300SDL, (sold) 125K, bought for 1$ "Kurt"

Are you positive of this?

I cannot recall if the '80 had EGR..........might have been the first year.

Thanks for your replies. I have taken the air cleaner cover off and made sure everything is as it should be. There are no obstructions. I live pretty close to sea level, so it isnt a thin air problem. I assume the egr is what is attached to the exhaust manifold and intake with a single vacuum line going through a thermal switch on the head. It holds vacuum, but I just stuck a golf tee in the line leading to it. Is it possible that I incorrectly set up the throttle linkages to cause this smoking but lets the car drive perfectly normally?

What did u change on the shifting? at 3/4 full throttle normally they smoke alot especially if u have it under alot of load or rpm. I'm assuming if the shift pattern has changed it's eather turning more rpm or under more of a load than before then this would be normal operation...

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2004 Infiniti G35 3.5L 6mt Coupe 73K miles 25.6mpg ytd
2001 Green Audi TT 225 AWD Roadster 71K 6sp 30.9mpg >>STOLEN<<
1982 300D Turbo 231K 120hp? 28.1mpg YTD

After transmission adjustments it now shifts through all gears at the correct timing with no noticeable flaring or harsh grabbing. I don't see how the transmission could be causing the problem because it blows a black cloud when revved up in park or neutral. I think the only logical next step is to pull the injectors and pop test them. Any other ideas?

In post #1 you stated that you replaced the injectors. If the problem remained after that task, why would you chase them again?

Problem solved! I sold the car...

what a trooper

I think 5 days is a record.

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