Beginning in early 2005 we started encountering problems with fuel contaminants in our heritage equipment power cars' fuel systems. We utilize twelve cylinder Deutz & Detroit power plants, running multiple units in train cars (power cars) with twin 300 KW generators. We found a great deal of water in our fuel initially, but in short order started experiencing sludge problems to the extent we had filters and fuel lines plugged to the point of losing power plants on our trains. Not having the ability to provide trainline power to individual train cars with our power cars caused us to use under car back up units. Most of our cars have these units, but not all; another problem.