No power. Poor fuel economy.

Biologicals growing in the tanks, or a bad fill?

The bad fill happened to a Cummins I drove, and it was a miserable winter after that, but shook it after the weather warmed, that ISX returned really warm fuel to the tanks and cooked it out.

It can foul up the injectors, too, because the microbes defeat the water separation in the fuel system. They are technically a fungus or bacteria, several different species, but are usually called fuel algae.

Pseudomonas will even grow in gasoline, but there needs to be water in the tank, too. The line between the fuel and water is where it grows, it needs both.

 

Actually black, and the filters catch the big stuff, plugs them tight, and on and on, there are additives called biocides, usually some formula containing borax that kill it.

 

Did this start suddenly or was it gradual, the black you mentioned was a clue to it being caused by bad fuel?

 

They make a biocide that you can put in your tanks to kill the algae but if your tanks are real bad you may be better off draining them and having them cleaned.