Puffs of black smoke

[crispyboy]

on the way home from a weekend camping trip I noticed that the truck was occasionally puffing out a cloud of black smoke. Engine runs smooth as always. The smoke cloud was random but would happen mostly when you would give slight throttle. There are no codes set.
2009 Ctd, efi live on stock power delete setting. The egr and egr cooler are still on the truck. Egr is unplugged. I have been running this setup for approximately two years.
Could this be a maf sensor? Boost leak? Injector issue?
Any thoughts on things I could check are appreciated.

 

[sag2]

MAF is not used on Cummins for fueling, only for EGR.

 

[cerberusiam]

Sounds like an injector malfunction, that is what we saw when one went bad.

 

[MichaelOverfield]

on the way home from a weekend camping trip I noticed that the truck was occasionally puffing out a cloud of black smoke. Engine runs smooth as always. The smoke cloud was random but would happen mostly when you would give slight throttle. There are no codes set.
2009 Ctd, efi live on stock power delete setting. The egr and egr cooler are still on the truck. Egr is unplugged. I have been running this setup for approximately two years.
Could this be a maf sensor? Boost leak? Injector issue?
Any thoughts on things I could check are appreciated.

Are you completely sure the EGR is unplugged? Even with a tune, the EGR if left plugged in, will do exactly what you described. If it is unplugged, perhaps the EGR valve might be leaking by.. Or as cerberusiam suggested... an injector issue. Though, I would hope that would have a DTC, but it might not.

 

[cerberusiam]

Mechanical injector failures will rarely show any indication other than smoke or engine roughness. The 3rd gen computers are not really smart enough to deduce a mechanical problem, especially if it is subtle failure.

 

[crispyboy]

Due to a death in the family (dad), having to travel to Florida to pick up mom, quarantine with her for two weeks back in KY away from my family, my daughter getting exposed to the covid bug at school so now another two week quarantine I haven't driven the truck in over a month. At least I can work from home. When I do go to job sites I have a company vehicle I can use on a temporary basis so the truck has just sat in the garage.

Thanks for your thoughts on this possible injector or EGR issue. I will have some time on my hands so I will pull the EGR valve and clean it. The connector has been unhooked and wrapped in electrical tape for some time. I also was thinking about a bottle of Stanadyne concentrated injector cleaner and watch for results. I have used Stanadyne warm weather performance additive in most every tank. Either it doesn't work as labeled or an injector is getting flakey.