Engine/Transmission (1998.5 - 2002) Black Smoke at Start: Why?

[SHovis]

On start my 98. 5 puts out a single puff of black smoke followed by a longer puff of grey smoke. This happens every time regardless of how long the truck has been sitting. Could have sat for one minute or one week. It's getting annoying, as I don't like to cover people with soot as they walk by.



I had it in to a diesel performance shop and they had no ideas for me at all. It happens even when the Banks box is unplugged and the engine is stock. This started about the time I moved to Utah which is 3000 ft higher than were I was in Minnesota. Could just be a coincidence.



Any ideas would be helpful. Thanks!



Steve

 

[16919]

Its normal... . all of em do it. Fuel+no boost=smoke

 

[hummincummins2]

chill man thats how all the 2nd gen 24 valve engines are. if you dont like it try to put on a particulate filter. but i dont see why you dont like it? every one here loves the black smoke!!!!

ps theres nothing wrong wit your engine, its a diesel you have to accept a little black smoke on the start and at full load.

 

[HookMeUp]

I live in Nebraska and everytime I go visit my Dad in Denver it does the same thing as far the grey smoke after start up. I always get a puff of black smoke everytime I start up. It's a diesel thing.

 

[johncameron]

When you start your engine the ECM requests X amount of fuel and you get XXX amount because the injectors are bigger. Too much fuel = smoke. The bigger the injector the more smoke there will be. My DDII's are 25HP less than yours and they puff a bit at startup.



John

 

[OL RATLR]

On start my 98. 5 puts out a single puff of black smoke followed by a longer puff of grey smoke. This happens every time regardless of how long the truck has been sitting. Could have sat for one minute or one week. It's getting annoying, as I don't like to cover people with soot as they walk by.



I had it in to a diesel performance shop and they had no ideas for me at all. It happens even when the Banks box is unplugged and the engine is stock. This started about the time I moved to Utah which is 3000 ft higher than were I was in Minnesota. Could just be a coincidence.



Any ideas would be helpful. Thanks!



Steve

It's a Diesel. :-laf

 

[SHovis]

Hi guys. I understand the 'it's a diesel' thing, but I've had the truck for 5 years and this is relatively new. The injectors are stock. It's been doing it for over a year now so I'm obviously not too worried about it Just thought I'd see what you had to say. Thanks. Steve

 

[WestTN]

Big injectors and stacked fueling boxes pretty well guarantee a puff at startup.

 

[drury]

Your move to a higher altitude exacerbated the situation. The air isn't as dense, so you're getting less oxygen. Less oxygen = more smoke. If you really don't like it, you could try some mods to increase the airflow, like a cam, BHAF, etc.

 

[InThinAir]

That was my guess. That you just moved to UT from a lower altitude. You will also notice it in Hairpin Turns when you accelerate away. I used to live at around 10k above sea level. Driving home at night I would see black smoke in the side mirror coming around the corners. It will always be there until you build some boost to counteract the effects of less dense air.

---Doug

 

[blacksheepdiesel]

Steve,

drury and InThinAir are correct. The air is less dense at your altitude which means less fuel is going to burn when starting. The amount of fuel going into the combustion chamber has not changed, just the amount of air to burn it. When you go back to lower elevations like where you used to be the puff will disappear. There is no mod to counteract this starting condition.

Godspeed,
Trent