Hi. Ny diesel D22 (1999) with 125000 miles on it developed a misfire rapidly leading to total lack of power. It starts, ticks over gives out alot of smoke, like undurnt fuel. I have changed the fuel filter, was some crap in old one, not alot, drained fuel and put new in. Blown out lines to injectors. Cracked each injector whilst running and each time engine lost revs. After blowing out and new filter engine ran ok for a short while. Seems worse going uphill and finally stops due to lack of power. Any ideas please