Ok, so here's the story.Kubota bx2200 D905 engine. Hurricane Sally drowned this tractor. it was completely submerged for 3 hours. Neighbor let it sit for 3 years. I took on the project, motor was locked up, wiring harness needed work. I took motor apart, rebuilt top to bottom. engine will start (runs clean, no smoke, run for about 4 minutes( black smoke starts) then shut itself off. If i pull fuel supply line, fuel pump is pushing fuel. If I pull injector line no pressure. If i let the engine cool, it will start right up and shut off in about 4 minutes. Removed fuel tank cap to check for clogged vent, no difference. No bubbles in coolant system. It does have blow-by, but i expect it as it hasn't run long enough to seat the new rings. So... I suspected the injection pump... rebuilt it. Now it starts runs 4 minutes and shuts off. New issue is it will not respond to the throttle(idle only). Obviously I now have 2 issues. anyone out there have any advise?