I'm trying to get a friend's 846 running. It quit on him last fall finishing up haying. It ran worse and worse on the way back to the farm, and when it quit, it wouldn't start again. We got it shoved in the shop this week, and I started by checking for fuel at the injectors, and have it at2,3 and 6. I have fuel at all lines at the pump. I get some black smoke and some popping, but it won't start. Head was off and went to the machine shop when he got ita couple of years ago, I think it got all new valves at that time. Injection pump was sent out also. Maybe a couple of hundred hours total since he's owned it. Pump is getting plenty of fuel. Any advice appreciated. Thanks.