Fyi

[gmctd]

Remembering lessons learned when lighting the ole BBQ pit\grill:

- add too much igniter fluid on barely lit coals and you get white vapors = too much fuel lowers temperature below combustion level, fuel never reaches ignition temperature but is above vapor point temperature

- add too much igniter fluid on fiercely-glowing coals and you get black sooty vapors = too much fuel not enuff oxygen, flame goes out, sooty un-burned fuel vapors

- add water where coals are too hot, burning the feast, reduces temperature = white steam vapors

So, in a heat ignition engine, which you got one of:

Black sooty smoke = water in fuel, where you have combustion but water douses flame B4 all fuel\oxygen is consumed

Black sooty smoke = too much fuel, where not enuff oxygen and flame goes out, but fuel was above combustion temperature

White vapors = fall\winter\spring = cold ambients, cold fuel, cold engine, not enuff heat for combustion, maybe too much advance = normal for cold clymes

White vapors = too much injection advance, where not enuff heat for combustion and early fuel further cools cylinder temps, some fuel never reaching ignition temps

Really bad symptoms: engine coolant leak into cylinder\exhaust, resulting in steam = white vapors, very stinky exhaust

 

[silverd]

Traveling on dusty roads for long periods can clog even worthy air filters and that demises the flow of air to combustion resulting in "too much" fuel hence black sooty smoke. Of course a connected CCV then starts drawing from the crankcase dropping oil level.
I was on a run this weekend and it was d u s t y and saw the other CRD in the group at the end of the run inspecting and brow beating his air filter just like me!! And they were dusty!

 

[Nursecosmo]

Traveling on dusty roads for long periods can clog even worthy air filters and that demises the flow of air to combustion resulting in "too much" fuel hence black sooty smoke. Of course a connected CCV then starts drawing from the crankcase dropping oil level.
I was on a run this weekend and it was d u s t y and saw the other CRD in the group at the end of the run inspecting and brow beating his air filter just like me!! And they were dusty!

Over fueling because of a restricted fuel filter is a commonly heard myth concerning modern computer controlled Turbo diesel engines. The computer controls the fueling based on the MAP signal. If boost pressure is decreased due to severe filter restriction, the computer will fuel accordingly, always at the optimum level and thus there is no smoke.

 

[Nursecosmo]

So, in a heat ignition engine, which you got one of:

Black sooty smoke = water in fuel, where you have combustion but water douses flame B4 all fuel\oxygen is consumed



White vapors = fall\winter\spring = cold ambients, cold fuel, cold engine, not enuff heat for combustion, maybe too much advance = normal for cold clymes

White vapors = too much injection advance, where not enuff heat for combustion and early fuel further cools cylinder temps, some fuel never reaching ignition temps
t

GM; I'm surprised. I don't think that I've ever seen you post an error like this.[-X
Advancing the timing results in MUCH hotter combustion and higher cylinder pressure. The temperature and pressure is in fact so high that if advanced much beyond ~16 degrees TDC, you will soon be looking for a new head gasket if you don't have fire rings and strengthened head bolts. Our little CRD's computer advances the timing in order to AVOID white smoke because of the slower burn of the fuel when cold. Because of modern emissions restrictions Diesel engines are not advanced to where they run most efficiently because of the NOx produced by the higher heat of combustion.
FYI a CI engine and a BBQ grill have very little in commonscrewy.gif

 

[gmctd]

Correct, and I agree: CRD systems have infinitely finer control over the entire injection event compared to mech-injected systems, incl those early EFI\mech systems - therefore you will seldom see white vapors from non-ignited fuel in a CRD system - at hi-rpm you will get increased heat (and oxides of noxious: hence, EGR) - however, when the system is acquiring faulty information from the sensors, even a CRD system will pass white vapors when too much fuel or\and too much advance is demanded due to incorrect feedback - at lo-rpm you will get decreased heat - other than that, white vapors are very scary, being symptomatic of coolant leak into the exhaust-side of the head - coolant-leak is accompanied by acrid\putrid exhaust odor - rich-burn is accompanied, of course, by raw Diesel fuel odor - and, we don't always love the smell of raw Diesel fuel in the morning.................

Almost fergot - Diesel fuel and igniter fuel have a lot in common: both result in white vapors when unignited due to insufficient heat - both emit black sooty smoke when at\above combustion temperature but not enuff O2 to sustain combustion - BBQ pit\grill is only thing most pople have in common when attempting to illustrate concept of white vapors vs black smoke in a heat ignition engine - but, that goes without saying, right?