First i changed piston and liner, hole in liner but then i had a problem with starting tractor ,the rack in injector pump was stiff ,cured that problem, put a new 90ah battery on today pushed diesel button in and tractor started, but have to have accelerator open full because it keeps coming to a stop the only way it keeps going is if i'm quick enough to get to diesel button and push it in,then it will stay reved up but it will come to a stop again, if i try driving it, very weak i think it something to do with fuel, ANY IDEAS???