greyish/light black smoke

[olboyowl]

what could cause this? its between 1000-2000 rpm under normal exceleration. also, you can see a pretty good haze at night with other car headlights behind you that u cant see during the day. to much timing? i haven't messed with main for awhile, but have lowered pilot timing not to long ago. maybe cuz its colder out? dosn't seem to be as bad when it warms up a bit, but its still there. just need some direction. thanks

[TexasCummins]

I think it's impossible to be completely smoke free, but it's very easy to get it to the point where you and I have it - nothing during the day but a haze at night. It's just a side effect of adding more fuel and timing. I think the only way to get rid of it would be go back to severely limited stock-ish timing and fueling. Someone more knowledgeable should chime in! :D

[AdamRRT]

I've got the same thing. Looks horrible at night in the mirrors huh? Haha.
Are you getting this on a multiple-event tune or a single event?

[olboyowl]

multiple. pilot quantity is only lowered slightly and blended, pilot timing is lowered through the daily driving range and never sees north of 27*. both are cut out at 2600rpm. duration is only slightly higher then stock until around 2400 rpm. fuel pressure is nice and linear up to 160mpa. max timing is at 46*. truck runs awsome. just wasn't sure if i could get rid of some more of the haze.

[icem237]

I have the same and It does have to do with the temps outside. I did something a while back and i cant find the tune where i fixed it. LOL so im going back through some notes. If i can find it ill let you all know! Also as a side note, check those air filters too.

[olboyowl]

i just went back through my file and lowered duration some more. it is only 10-30us over stock up to 60mm3, then picks up gradually to 100mm3, then its on. will get results up tomorrow. yeah, my filter does need cleeeened bad.

[THEFERMANATOR]

A plugged fuel filter will cause smoke, and is normally the first place I look when mine is smoking. Also I have found that taking teh timing much beyond 50-55% will cause hazing as well as a light grey/black smoke during the day.

[AdamRRT]

Oh wow that's some super low timing. But good point. Maybe that low timing is partly responsible for the stock tune's lack of haze.

Also is that on a multi event, Fermy? I guess that's not really crazy low if preceded by a pilot shot.

[DODGE74]

Try and pull some more duration out of the 30-60mm3 and 25-100mpa. I've actually pulled so much out of mine that I'm actually below the stock pulse with and I'm running stock injectors. Since I've done that it has really helped the keep the smoke down.

[olboyowl]

don't have much feedback. it was raining here this morning so i couldn't tell what it was doin. gordon, i did pull a gooood bit out of it yesterday. i checked with the comparison tool and had it below stock levels at a few spots and really close on the rest. off the next 3 days, so i'll have a chance to mess with it. also, what are some of u running for timing at idle? i'm at 18* in main. anyone running higher/little lower? trying to see what idles the quietest/smoothest

[Dmaxink]

Guys ever consider instead of pulling so much duration down in the main injection to maybe try using your mm3 limiters to bring it down to the desired amount of uS? Also, make sure when you decrease your duration that the ecm doesnt demand more fuel and automatically increase mm3 in the process. This may have some chasing their tail... just my .02

[olboyowl]

makes sense. i'll give it a shot. thanks kory

[DODGE74]

don't have much feedback. it was raining here this morning so i couldn't tell what it was doin. gordon, i did pull a gooood bit out of it yesterday. i checked with the comparison tool and had it below stock levels at a few spots and really close on the rest. off the next 3 days, so i'll have a chance to mess with it. also, what are some of u running for timing at idle? i'm at 18* in main. anyone running higher/little lower? trying to see what idles the quietest/smoothest

I'm not running near as much timing as some of you guys. I'm only running about 13* at idle and it tops out at 40*


Guys ever consider instead of pulling so much duration down in the main injection to maybe try using your mm3 limiters to bring it down to the desired amount of uS? Also, make sure when you decrease your duration that the ecm doesnt demand more fuel and automatically increase mm3 in the process. This may have some chasing their tail... just my .02

Thanks Kory, I will also give that a try. I was pulling more and more fuel out of it and I started scratching my head wondering how it still runs its butt off even when I was below stock mm3 levels with stock nozzles.

[THEFERMANATOR]

Oh wow that's some super low timing. But good point. Maybe that low timing is partly responsible for the stock tune's lack of haze.

Also is that on a multi event, Fermy? I guess that's not really crazy low if preceded by a pilot shot.

All of my tunes use pilot in them under 2700 RPM as I can't stand that 12 valve or powerstroke rattle. In all of my power cells though I'm currently running 55% for my timing down from 60%, and I noticed a definate decrease in smoke even though I increased my fuel by 10%. In the cruising areas I'm running about 2 degrees over stock, so about 3-5 degrees of timing. I ran it up to 7 before, but got alot of hazing and rattle when I would lightly roll into it. Also I found the pilot correction tables helped alot with reducing mid RPM hazing, but I don't know if they have made one yet for the CUMMINS guys.

[AdamRRT]

Thanks Fermy. I'll try this lower timing.

[THEFERMANATOR]

Also another thing I found with my DURAMAX is pulling pulsewidth can actually increase smoke output. My 40% over tune only really had added fuel way up in the pressure and MM3 of fuel and it hazed a pretty noticeable amount. Yet my50% over tune has added pulsewidth at basically anything over an idle and doesn't hardly haze at all now.

[AdamRRT]

Now that one just makes no sense in my poor little head. haha

[icem237]

All mine turns out to be was dirty air filter. All the night time smoke is gone. Just a little soap and water on the prefilter and vacuumed the filter itself and its been perfect. I use one of the amsoil filters .

[olboyowl]

a buddy gave me a brand new afe filter that i swapped out last night. did seem to help some with reducing smoke. could have been me pulling more fuel. wish i would have ran it first with the fuel pulled out of it and then ran it again with the new filter. reguardless, a step in the right direction. kory, on the barometric tables under the fuel limiter, boost tables, is the psi at the top of the tables reffering to boost? im 98% sure it is, but want to make sure. also, if i have my fuel limiter boost table set up from 0-35psi and the barometric table is set from0 -14psi, should i mirror my barometric quantities to the fuel limiter boost? ex. fuel limiter, boost is at 33mm3 at 7psi. should the barametric tables be set to around 33mm3 around 7psi or can there be a 20-40mm3 difference? right now, my baro tables are all at 140mm3 accrossed the table.

[icem237]

What gets me is I havent pulled any fuel away from my dration table. Have added duration. But i do not get any haze till I cram the pedal, then its just a gray haze at most. highest timing is 49 degrees.

[icem237]

http://i800.photobucket.com/albums/yy290/W4CXT/63177923.jpg

http://i800.photobucket.com/albums/yy290/W4CXT/71f8f51f.jpg

[icem237]

Guys as a side note when i just recently made my no pilot from the same tune in the pictures above all of the mid range smoke seemed to go away for the most part. Makes me think tuning pilot was the cause for alot my issues with grey smoke. I have been on single event tuning so long , kinda slipped my mind lol ....

Anyway Ill drive on this for a while in varying conditions and see what happens.

[icem237]

Ok for clarification purposes, I do still get some light smoke . But it is nothing like what i experienced before. Much more tolerable.

[Dmaxink]

a buddy gave me a brand new afe filter that i swapped out last night. did seem to help some with reducing smoke. could have been me pulling more fuel. wish i would have ran it first with the fuel pulled out of it and then ran it again with the new filter. reguardless, a step in the right direction. kory, on the barometric tables under the fuel limiter, boost tables, is the psi at the top of the tables reffering to boost? im 98% sure it is, but want to make sure. also, if i have my fuel limiter boost table set up from 0-35psi and the barometric table is set from0 -14psi, should i mirror my barometric quantities to the fuel limiter boost? ex. fuel limiter, boost is at 33mm3 at 7psi. should the barametric tables be set to around 33mm3 around 7psi or can there be a 20-40mm3 difference? right now, my baro tables are all at 140mm3 accrossed the table.

Going off the top of my head ( no laptop in front of me) The baro tables psi is in fact related to baro (sea level 14.5)...honestly, these tables are good to max out in my opinion and use the expected boost table to limit mm3... that table is really sweet to use as the main limiter... just my .02

[olboyowl]

i modded the baro tables and it negatively affected the performance of the truck so they are max'd out again. i think im trying to get to carried away with smoke reduction. limiters are not getting touched for awhile. i think i'm at my trucks limits for now!

[2007 5.9]

i modded the baro tables and it negatively affected the performance of the truck so they are max'd out again. i think im trying to get to carried away with smoke reduction. limiters are not getting touched for awhile. i think i'm at my trucks limits for now!

Light to mod throttle smoke is more timing related than fuel.

I stopped my single tune for this reason...I am starting to think our open bowl design isint forgivable to a single event as the closed bowl design of the 24v and early CR.

[skneeland]

...I am starting to think our open bowl design isint forgivable to a single event as the closed bowl design of the 24v and early CR.

without a doubt its an inferior choice for piston design IMHO. Cummins must have also agreed, as they returned to the other style of piston for the 6.7L. Anyone in the midst of a rebuild would be silly to not swap over to 03-04 pistons and injectors.....