We were in Alaska and rig was getting harder and harder to start. When it finally started it was lurching and cutting out. I found a tech and he installed a new fuel filter. He had me give him a bowl and he poured the contents of the filter into the bowl and you could see little black flecks. I thought it was dirt in the fuel. When we got to Montana she quit. Had a new fuel pump installed. When I got home my mechanic told me the tech should have known when he saw the black flecks in the gas that the pump was disintegrating and should have replaced it then.