I have a 4500 fwd that suddenly quit running this past weekend while I was shredding a pasture. When I tried to restart, it fired up but choked and sputtered with a black smoke coming from the exhaust. When I throttled up the idle it really started choking. When placed in gear the motor idled down and cut off. Did this several times then I left it for awhile and came back and it fired up and ran fine for a short time then did the same again. Does this sound like a fuel filter clog or possibly a clogged injector. Anybody got a clue as I plan to try to get it running right this weekend.