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El_mavi · 11-17-2022, **(Subject: CM870 Black Smoke on high altitude )**

Hi folks, I own a 2005 Intl with CM870 Isx 475 Hp. I bought the truck six years ago and bought it with Egr unplugged and nothing else done regarding Egr and Ecm demandate. I have been reading, learning and practicing on my own spares and decided to give a try with @m*m^2 for cm870 from Zero Crisis. I thought that would make the black smoke-soot problem but apparently not. On my knowledge black smoke could be too rich mix so too much fuel or too little air. Tried air filter, no air filter and still the same. And it only happens on high altitude and when shifting from gear to gear. I am thinking maybe turbo is not that good anymore, or actuator maybe. What would you do for troubleshooting? I would like to start from actuator then turbo obviously because dont want to spend a lot on turbo and then find out it was the actuator or the vgt commander valve. Any tips where or how should I start? I could share the Calterm Document if someone would like to take a look. Thanks in advance.

Edit: both cams were replaced not too long ago and an inframe made about a year ago. I suppose all the harm made by running the truck for years with egr unplugged it is solved now. It had worn rings and a lot of blowby but not anymore.

tree98 · 11-17-2022, **(Subject: CM870 Black Smoke on high altitude )**

@m*m^2 is for the cm871 not the cm870. I don't know what the differences are but I do know there are other parameters that must be changed live on an 870, you can't just use an overlay on them. Also the 870 turbo is air actuated and a lot slower to react than the 871 electronic turbo. I'm assuming the turbo tables are different.

hhow55 · 11-17-2022, **(Subject: CM870 Black Smoke on high altitude )**

Go to quickserve.cummins.com, and you will find a tab in sympton search for black smoke.

hhow55 · 11-17-2022, **(Subject: CM870 Black Smoke on high altitude )**

Excessive black smoke.
Conditions :
n/a

Action Specification/Repair Next Step
Interview the driver and verify the complaint.

n/a

Is the engine symptom Excessive Black Smoke?

YES

Repair :

Perform the troubleshooting steps in the recommended order listed below:

Step 6 - Air Handling Checks
Step 4 - Fuel System Checks
Step 5 - Injector Checks
With EGR - Step 7 - EGR Checks
With EGR - Step 10 - EGR Differential Pressure and Exhaust Gas Pressure Checks
Step 9 - Base Engine Checks.
Perform the troubleshooting steps suggested in the repair procedure
Is the engine symptom Excessive Black Smoke?

NO
2D

El_mavi · 11-17-2022, **(Subject: CM870 Black Smoke on high altitude )**

(11-17-2022 )tree98 Wrote: @m*m^2 is for the cm871 not the cm870. I don't know what the differences are but I do know there are other parameters that must be changed live on an 870, you can't just use an overlay on them. Also the 870 turbo is air actuated and a lot slower to react than the 871 electronic turbo. I'm assuming the turbo tables are different.

I found some info about @m*m^2 version specifically for cm870 and some posts about correct procedure related to Calterm. I didnt use an overlay and did it offline from a factory clean cal with bench harness, I did made the Ram live edit after that when installed on truck.

It is working ok because black smoke had it before the Ecm editing, I just thought it was going to get better with it but I will need to start checking physically once truck gets back home.

Rawze · 11-17-2022, **(Subject: CM870 Black Smoke on high altitude )**

That official document is here: http://rawze.com/forums/showthread.php?t...0#pid53580

and it is not an exact fit for every make and model truck.. the '*_MCF_*' tables have to be adjusted per make/model vehicle.. and some of the logic settings vary from truck to truck... it is a ball-park to get someone close.. but not a perfect glove fit for any one vehicle. -== NO PROGRAM EVER COULD BE because there is just too many variations of trucks.. and engine hardware out there.

get with forum member 'running rough' .. he does a lot of the CM870's on here.. maybe you made some mistakes, perhaps missed some things, or simply need things adjusted for your specific truck.. who knows. -== but it can very much also be simply a mechanical issue as well.

And by the way.. if you shift the truck hard.. a puff of black smoke is inevitable on a deleted engine, simply because of turbo lag between hard shifts. It is a big diesel engine with a large charge air system, meaning there is a lot of lag in the turbo response vs. fuel demand when getting on it suddenly. This especially on an air operated vgt one like the CM870 has. That is how they behave when running efficiently when there is not excess boost running thru it.

Pd6cas2 · 11-17-2022, **(Subject: CM870 Black Smoke on high altitude )**

My CM570 used to smoke between gears no matter the conditions or my foot throttle pressure. One day I called YTS Turbo , replaced my old turbo! Problem solved.