I changed the fuel filters on the bus today because I thought it was smoking a little more than normal and low on power. I always empty the filters into a clear container just to see if the filters were doing their job. The secondary filter was clean, the primary filter had black carbon looking particles in it. Looked like instant coffee granules,for lack of a better description. Anyone care to venture a guess what I am describing, and what if anything, I need to do about it. Thanks Glen.
Not sure if your coffee grounds are coming from the fuel tank, or the fuel lines. Look at your fuel filter soon again to see if there is more.
With your reduced power and increased smoke, I would look at your air filter (s). If they are dirty like restricting the air intake, that will cause low power and more exhaust smoke.
JC
JC the fuel filter change put it back like it used to be. It has four oil bath air cleaners so I don't think they are a problem but will inspect anyway,thanks.
Coffee grounds looking stuff may be the inside of the rubber supply lines breaking down also...