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#1
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Older diesels didn't have the emissions requirements, so black smoke was not prohibited (to a point).
I agree with others, that the diesel will run lean most of the time, it has all of the air it needs with no throttle on the air supply. To increase power, you increase heat. To increase heat, you increase fuel. Fuel is air + diesel fuel, the air is already there so you turn up the fuel. When diesels were allowed to smoke a little, it was common practice to overfuel at full-throttle. Even though the excess fuel isn't burning completely (thus the smoke), it is creating a little more heat = a little more power. You can overfuel to a great degree and get more power, ever watch a tractor pull? Diesels at a drag race? The efficiency isn't there, you're getting less energy per gallon of diesel, but you will get more energy with more fuel to a point. It also will create lots of smoke and too much heat for the engine to last, but it is a cheap and simple way to increase power.
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![]() Gone to the dark side - Jeff |
#2
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charmalu,
U have a vacuum controlled Injection Pump (IP). I had a Perkins Diesel in a Fordson Major Diesel (built in England) Tractor engine that had that type of IP. There was no mechanical linkage to the IP. Seems like my old 59 180D MD pushrod Diesel had that type of system too. It also had another flapper valve in the intake manifold that would close if the engine ran backward. P E H |
#3
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The Alda does nothing directly to the boost, it modulates fuel flow relative to boost.
I know, more fuel will likely increase the boost indirectly, and then the ALDA will allow more fuel.
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![]() Gone to the dark side - Jeff |
#4
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it simply cuts the fuel going to the engine before boost comes up.
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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac? As long as they would add one additional commandment for you to keep thy religion to thyself. George Carlin (Wonder where he is now..) 1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won. pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt. |
#5
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u need more air just turn up your turbo all the way and be sure to mash the pedal all the way as much as possible..
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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 |
#6
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Good discussion. Learning a lot.
I'm not a Diesel expert (yet) but I think one reason Diesels smoke when under load is there is a lag for the exhaust to spin the turbo faster and get the extra air into the cylinders. Just a thought. So, I concur, there's unburnt fuel coming out the tailpipe. It could be as simple as the lighter fuel components have evaporated and left behind a lot of gunk and gum. I'd say change the oil and oil filter (it's a must do if it's been siting that long--transmission fluid and filter also a good idea) change the air filter, dump in a dose of fuel treatment/injector cleaner and go for a nice long ride. Fill up with a fresh tank of Diesel fuel and a double dose of fuel treatment. Run it for a while then change the fuel filters. If that takes care of it, great! If not, dig a little deeper. |
#7
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jamesNB,
Some of your post may have merit but changing the fuel filters when there is no power loss is ridiciulous. The reason diesels smoke is because the mixture is too rich. Gasoline engines will also give off black smoke if the mixture is too rich. Ever have a stuck choke or bad carburator? Ever see a tractor pull where the Diesel tractors pour out volumeinous amounts of black smoke? That's because the IPs are adjusted for a very rich mixture and maximum power. P E H P E H |
#8
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I must have the only MB in the world that does not bellow, belch, or blow huge clouds of black smoke. I never get black smoke, even at WOT...no smoke. Therefore, all YOUR MB's must be out of adjustment.
![]() Black smoke = unburnt fuel....heck it even still smells like diesel. And every time I see it, I think....what a waste! Frankly, I don't understand the sense of pride some have in being able to produce these "big black clouds of smoke" when merging on the freeway. Why does wasteing fuel and spewing black smudge over other motorists seem fun or cool?? My rant for the day is now ended.
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Mark 1983 300TD Wagon Even a broken watch is right twice a day |
#9
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Re-read my post. Maybe it's not clear but I'm not saying changing the filters will fix the problem. I'm saying change the filters because they will need it.
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#10
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You've got a turbo in good tune Mark. I sold M-B new when the turbos came out, they didn't smoke at WOT, big difference from the NA engines. They can be "tuned" to smoke, more power from more heat, some people choose that but tuned to original specs they will not.
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![]() Gone to the dark side - Jeff |
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