This 1981 300D N/A came to me, with lots of issues, but the most predominant is the black smoke on acceration and no power. It feels as though the throttle is only going to 20%. I adjusted valves and verified the throttle linkage goes to full. The crank case breather system in the air filter box was broken, so I replaced the box with a good used one and verified that the breather system was all clear. Not too much blow by. Engine starts and sounds healthy. Thoughts?

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Andrew Villasenor
805-720-5057
1984 300D turbo 5-speed manual(daily driver)
ALL MY DIESELS RUNNING WVO
Everything is for sale for the right amount
Ebay Store

Timing chain??

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General George - 1967 Land Rover 2a SWB 1983 OM617 Turbo

Look for an EGR, block it off (both the exhaust side and the intake side) with steel when you find it (not aluminum cans please).

My first MB was an '85 euro 300TD, NA engine but a five-speed transmission that made up for the lack of turbo. When I bought the car, it had very similar symptoms: black smoke and very little power. I chased that for almost a year: filters, rebuilt injectors, IP timing, new timing chain, multiple valve adjustments. Finally I learned from Dr. Marshall Booth (RIP) that blocking off the EGR would give a slight boost in power, so I did that and immediately it was like I had a new car.

The EGR valve can fail in the open position, and then your car is breathing exhaust fumes 100% of the time, and there is not enough oxygen for complete combustion of the fuel.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Carefully check the injection pump timing. Your issue is also quite typical of a seriously retarded injection pump. No power and lots of smoke. Also make certain when testing the injection pump by the drip method that the first cylinders cam lobes are both pointing upward at about a 45 degree angle.

A injection pump installed and timed on the wrong stroke by someone will make a horrible running engine even if it is timed properly. Smoke really bad and no power to speak of. It does happen. Another possibility is you may have a seriously pissing injector or two. Still I would leave that till last to check. I kind of have issues that one pissing injector would reduce power that much as well but for all I know it might. Instead I would expect smoke primarily.

Of course it can be other things but this is where I would look first after making sure the air filter is not really bad. If uncertain on the air filter just running the car for a few minutes without it will do no harm.

Also these are old engines and you may have a really bad stretched out timing chain as well so check that too. It is not hard. Elimination of the egr is easy as well plus desirable anyways even if not faulty.

You are obviously getting lots of fuel but not burning it properly. So obviously it is either a lack of oxygen or fuel being injected at the wrong time. Nice to hear the engine does not have a lot of blow by as well. That is almost always a good sign on these old buggies.

What I and others have mentioned above should get you by this problem. Then when you get it running well give the fuel system a good tune up. It improves a lot of things on these N/A engines. I have an old 77 300d that does well for what it is . Especially once I tuned it up.

According to the lifted obnoxious diesel truck guys, smoke = power. Are they telling a lie?

At a certain point, additional fuel becomes a waste. If it comes out black, then it was not fully burned, and any potential thermal gains are lost to the atmosphere as soot.
Kind of like drinking a gallon of water, your body will only be able to use so much,then the rest is urinated out.
Some diesel guys think..... why stop at a gallon of water, 10 gallons is better aint it?

In those cases black smoke still means that more fuel is being delivered than burned. When the engine has a huge turbo it means that ridiculously large amounts of fuel are being pumped into cylinders (hence the power) but not all of it gets combusted because there's not enough oxygen. One could put on an even bigger turbo but at some points the pistons are going to melt. It's a wasteful way of showing off in my opinion even though some may see it as pushing the limits.

The case of OP's engine is different though. Still more fuel delivered than burned but the lack of power suggest some sort of malfunction in either timing or air delivery.

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General George - 1967 Land Rover 2a SWB 1983 OM617 Turbo

I should have but a at the end of my statement, I know that over fueling is a waste and does nothing on a stock ish motor.

Diesel pickup are semi common around here, there might be one or two that isn't driven by some idiot with a smoke box.

i did realize that you were being sarcastic but only after i posted my response

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General George - 1967 Land Rover 2a SWB 1983 OM617 Turbo

Don't lie to us. You secretly want to roll coal .

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

What does the smoke smell like?

Retarded/late timeing on My Volvo diesel did not result in black smoke it was white then as I corrected it gray and then normal.

Unforunately there is more then one thing that can cause black smoke. Be thinking of too much Fuel, not enough Air or poor compression.

Fuel Injection Pumps generally do put out too much Fuel.

It is easly enouh to find ouf if the Air inlet system is blocked.

The Compression issue could be a blown Head Gasket (compression test). The other end is something bad happend to the Cylinders/Pistons/Rings.

Not related to the above is if it has a Turbo Oil could be leaking out of the Exhaust side if the Turbo and if the Turbo is not working that could account for the power loss.

Line up the Timing marks on the Camshaft Gear with the one on the front Bearing Tower and look down at the Crank Damper and see what degrees are the Pointer indicates.

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84 300D, 82 Volvo 244Gl Diesel

This might have something to do with it :

"" Andrew Villasenor
1984 300D turbo 5-speed manual(daily driver)
ALL MY DIESELS RUNNING WVO """

If the smoking car in question isn't yours, do you have any history of the car?

Black smoke is not enough air / too much fuel for the rpm the motor is at.

Does this engine have a throttle flap in the intake? With the engine off have someone push on the peddle and look in the intake to see if the flap goes full open. ( Don't do this by moving the under hood linkage, you want to see actual operation. )