White smoke is probably condensation if its not been run in a while. Black is fuel, could be a few things cause that. have you checked for any engine codes By bridging te1 and e1 in the diag port? (Someone correct me if i got the wrong pins) sometimes they have codes but dont throw the c.e.l on It will cause the engine light to flash in a sequence, if its a constant flash its clear but if its spaced out its throwing a code