Too much fuel

[Darth Wraith]

Hi! I bought a 1500 Drifter from 2002. It was non-functional since 2015 spring - the former owner had a knee injury. When I start it is "dieseling", with a lot of black smoke, Apparently the mixture is very rich, but the ECU does not give any error. Before spring of 2015 the former owner claims it was running normally.