Well its finally gotten cold in Alabama and my car is not likeing it. In the morning when I go to work I cannot take it above 3-4000 rpm or it will stutter, sputter, backfire and spew black smoke. The RPM that this happens will climb as the car warms up until it goes away mostly. Tonight I mixed with a 240sx(spanked it of course) but it did pop at about 6800 the car was all warmed up by the time this happened. Since the black smoke indicates a rich condition whats probably going on ?