I have an AFX serial# CAT 725. The truck was working the other day when the operator stopped the truck because the engine started to bellow white smoke out of the exhaust. Diesel fuel is pouring out of the turbo, I think I know the answer to the problem but would invite some insight.
Think you have a split tip on an injector dumping fuel into the cylinder. Best case tip just split and you can get by with just and injector. Worst case the tip has dropped into the cylinder, made a mess out of the piston and head, then damaged the fins on the turbo on the way out. Seen this a lot on some of the earlier E model truck engines.