Intermittend black smoke

[Ficm]

Hey guys,

 

I'm working on a late build 2004 6.0L with lack of power and severe misfire at idle, truck does not want go anywhere. Noticed during my visual inspection air filter minder not plugged into air filter.

 

I diagnosed it to be combustion air entering fuel system on right hand side bank 1. During power balance injector 1 and 7 -50rpm and eventually takes down 3 and 5. Relative compression 0 across the board. Fuel pressure 55PSI. Fuel sample good. I replaced all 4 injectors with OEM and upgraded fuel pressure regulator (blue)spring. Cleared codes misfire gone and power balance even. I noticed during my road test when truck gets hot, slight hesitation followed by puff of black smoke accelerating from stop. Monitor pids VGT appears ok does not look like turbo sticking. Air filter clean. EGR valve lazy during sweep test. Replace EGR valve, black smoke still evident. No codes. Any thoughts on what could possibly cause the black smoke condition?

 

Could my bank 2 injectors possibly be lazy? Thank you for your input

[Keith Browning]

A little black smoke could be considered normal on initial acceleration as long as it is not too heavy or prolonged. The other bank of injectors could have issues depending on what it was that caused the problems on the right bank whether it be low fuel pressure or fuel quality, do understand that the root cause of your injector failure affected the entire set of injectors.

 

I have noticed over the years that after certain repairs the exhaust is loaded up  causing turbo lag and all kinds of crap coming out of the tailpipe - especially if the truck has not been running well for a long time with EGR valve and injector  problems, heck even FICM performance issues can load up a DOC. Before beating your head against the wall make a good visual inspection of the CAC system for leaks, and the exhaust system pre-turbo for leaks and address those. Then try updating the PCM/FICM if you haven't already. Then Clear all DTC's run a KOEO self test so the PCM can learn the EGR valve closed position, then cycle the ignition, and run the truck. Then take it out for an semi-ABUSIVE road test to accomplish two things. First, get the exhaust hot to help burn up any soot loading in the DOC. I like to run down the highway and put the transmission in a lower hear to keep the RPM's all the way up and still keep up with traffic. Run down the highway for 10 minutes or so. Second, then perform several WOT accelerations from a dead stop and then perform several WOT accelerations while already moving, like when you are entering traffic or passing another vehicle. This will also help clear out soot from the exhaust.. Usually this puts the snap back into the truck - at least it seems to work for me.

 

After that, if you still have issues it would be prudent to look at some PIDs and verify that your turbo is functioning properly. Pinpoint Tests "KA" will help identify sensor issues EP/MAP/BARO