black smoke and a cough

[Rawze]

(02-26-2020 )slowpoke Wrote:  isx cm871 emmisions all reconnected did one run Toronto to jersy truck ran good empty down but noticed stacks were black way more than when i was del*ted. loaded getting on intersate truck coughed 4 times fraction of a second lose of power. had warmed engine to 180 before i left. i could see black smoke about 2 seconds after full throttle trail to back of trailer then stop. i did install used doc and dpf wanted to make sure egr wasn't going to leak and destroy brand new ones. can an isx still produce black smoke through a dpf filter if something else is bad. going to pull egr valve. i hadn't changed delta p . or exhaust back pressure sensor yet. will replace dpf with road warrior just want to make sure everything else is fine first. so can an isx 871 roll black smoke with an intact dpf is main question.

(Just some experiences i have seen with aftermarkets)...
I HAVE NEVER SEEN an aftermarket DOC or DPF work even half-way worth a damn.. WASTE OF GODDAMN MONEY! -- THERE IS A REASON THEY ARE CHEAPER -- THEY ARE MISSING HALF OR MORE OF THE PRECIOUS METALS, THEY ARE OFTEN NOT DESIGNED CORRECTLY TO PROPERLY CAPTURE SOOT, AND/OR SOME BRANDS HAVE ZERO PRECIOUS METALS AND GIVE NOTHING BUT GRIEF TO THE PERSON WHO THOUGHT THEY COULD GET BY WITH IT!
I have seen this at least 2 dozen times.

Did you use an aftermarket dpf/doc? -- if so, that could easily explain some of the black smoke getting past the dpf. THAT or when the element is cracked, or has been washed with steam or water and it is ruined, they will allow black smoke past them. I have also seen smoke get past one if it is really really severe issue (like bad turbo, failed injectors, failed/fouled fuel components, etc.) on the enigne itself causing a ton of black smoke to be put through the exhaust, and that also will clog that DOC and DPF filter incredibly fast too.

so , NO-- NOT NORMALLY! ... Almost always, when there is black smoke getting past that DPf, either the element is cracked, no good, etc... or your engine has some kind of severe ..and i would put heavy emphasis on the word SEVERE ... problem where it makes waaay too much smoke problems.


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More on "Un-doing" a deelted truck in general...
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If you did not replace or pull off and clean up ALL of the egr piping, the egr valve ... and since it has been deleted in its past -- PULLED OFF, DE-SOOTED, AND ACID-BATHED the EGR-cooler,.. then it is NOT LIKELY to operate correctly. As it will get annodized on its insides, packed up with carbon and soot, and all sorts of other internal damage to its ability to properly cool the exhaust gasses after it has been sitting dormant for a long time on the side of that engine. <- Same yhing with the egr valve, the corssover tubes for the Delta-P sensor, and DPF Delta-P sensor and its crossover tubes, and a whole lot of other piping and sensors in relation to those systems.

If that egr cooler was dormant for a long time, and suddenly you started using it wihtout cleaning it out properly, .. a chunk of carbon could have very easily come out of it and chewed up the exhaust vanes of your VG turbo (up by the VG vanes) ... I see this waay to often, hence the reason why a person MUST pull that thing off and clean it all out and ensure it is not annodized or packed with old soot/carbon before its re-use into the system. Same ting with the egr valve and piping ... a piece of dried carbon/soot, hard as stone can come loose and damage an intake valve / cause compression loss or other problems for a cylinder in a hurry.


AND THEN there is the Doser injector, its fuel line, the Doser fuel pressure sensor circuit, and everything associated with that thing that can get clogged up because of sitting without use for long time not being used etc.. All the extra heat off the back of that turbo from a deleted engine (and especially a bad delete), cooks the fuel inside it and screws it up real nice. -- Replacing the Doser injector is the proper thing to do if you have hopes of the system to operate again with any kind of success.

Lot Rot sets in quickly with the entire system, its piping, and the components for the EGR and emissions systems. EVERY SINGLE LINE AND PIPE AND SENSOR AND COMPONENT even remotely related to the emissions systems should have been pulled off that thing inspected, cleaned, tested and a determination for possible re-use made, replaced, etc.


Sometimes this type of turbo damage cannot even bee see until the exhaust housing is removed off the turbo, so an inspection of the Vg vanes themselves and it alignment ring are looked at.



LASTLY,.. just because you put those systems back on your truck, DOES NOT MEAN it will magically fix that engine, or even work correctly due to age and wear on the engine itself. things like any more than 1 gallon every 8,000 miles or so oil consumption will make that system always complain, any other problems like old injectors that have bad spray patterns, worn out exhaust impeller or VG ring on the turbo, and a LOT OF OTHER THINGS that cause those emissions systems to not ever be happy and run correctly to begin with.


IT IS TRULY an up--hill battle to re-install and get running again all those systems if they have been switched off for any length of time +PLUS+ whatever engine ailments in its past that had caused someone to remove them in the first place.

Be thankful it is not a CM2250 or CM2350 .. Then your also fighting and dealing with dried up DEF lines and hoses, def doser injector issues, and replacing some very expensive things + removing the DEF tank and flushing it out of all the dried crystallized DEF and all the systems related to that thing. -- That is another nightmare all in itself too.

JUST sharing some thoughts and experiences with this subject. Hopefully you did most if not all of this stuff and took the time to go through all of it before assuming you could just slap everything back on expecting it to just magically work again without serious problems. Typically it takes about 3x or 4x the amount of time and efforts to get those systems to work again vs if they had been properly maintained and fixed (before the delete) to begin with.

and NO, that thing should not be making any kind of black smoke at all. White smoke on occasion whenever it makes a regen cycle going down the roads, but only on occasion, and usually only in cold weather... but not black smoke. something is very wrong.