The most likely cause would be the o rings on the injectors them selves, the injection control oil pressure is just above the fuel on the injectors and when the o rings let go oil is usually found in the fuel.
found the problem. each bus had one injector leaking fuel directly from the injector housing itself. replaced the injectors and no more problem. I pinched of the fuel return and pressurized the fuel rail with the valve cover off. fuel squirted right from the side of the injector.
diesel in oil
Posted - 05/28/2015 : 1:38:14 PM
