Smoke. Good/Bad?

[superbro]

Hey guys I was wondering if smoke is good or bad. I have my timing advanced a little and it never smokes. Should it? The only time it dose is on cold mornings.   

[745 turbogreasel]

smoke = wasted fuel.

[superbro]

Ok. But shouldn't it smoke a little? Like getting on the freeway? I'm trying to find out if I'm running a little lean. 

[mystery3]

Anytime you take your foot off the accelerator your diesel is running "lean."  There is a lot of reading/research on this site regarding the IP, mods, timing etc. That said my 1.6 doesn't smoke except for a few seconds on cold starts but it is slow as hell.

[8v-of-fury]

When your foot is not on the pedal, there is no fuel being injected. So feel safe, that engine breaking has no effect on mileage.

It should smoke a little bit, Bentley calls for a light grey haze under WOT.

[Rabbit on Roids]

diesels always run lean. even when you are blowing a black cloud out the back, its still running lean.

[81 vw pu]

When your foot is not on the pedal, there is no fuel being injected

Fuel is still being injected when you take your foot off the throttle, otherwise the engine would die like turning off the key.

[burn_your_money]

Fuel is still being injected when you take your foot off the throttle, otherwise the engine would die like turning off the key.

No because the car is now driving the engine. If the pump were to continue injecting fuel it would not slow down. As the RPMs approach idle then the pump will slowly start injecting fuel so that the engine will maintain idle and not stall.

[Turbinepowered]

If you increase fueling to the point of it smoking you might gain a little power, but you will pay the cost in fuel economy any time you play.  Blowing smoke is also an indication of high EGTs.  Even if EGTs are not dangerously high, under-fueled is ALWAYS better for engine longevity.   

For diesels. I can't count how many times people have worried about being "too lean" with their first diesel...

[Rabbit on Roids]

they are still lean, even with a black soot trail behind them.