black smoke from b16a

[elaxxx]

recently my car has been smoking alot and having really really bad gas mileage and every once in awhile it will back fire or if i have it at full throttle and it will have a lot of black smoke coming out the back... i have a 89 civic hatch with a b16a any ideas??
if this makes any diff i was having trouble having it fire on the 3 cylinder so i replaced the distributor cap (msd) sanded off the corrosion that was on the button inside the distribuor cap and noticed on the old distributor cap that the prong for the 3 cylinder was green and not copper like the other ones... then i also replaced the wires with msd wires and the pluges with boshe plat 4 it fixed the problem with the 3 cyclender not firing but now there is the smoking problem.. also my car has a msd igntion system its that silver sports compact one. any ideas of what else i could replace that could be causing the problem
thank you
tyrell

[civickiller]

your running really rich which is causing the black smoke. pull that plug again and see if its sparking all the time with a strong spark, also check to see if theres oil or anything on the spark plug