My 02 Tahoe will turn over but won't start .. on 1995 Chevrolet Tahoe

It starts when it want ... But when it do start it pushes out black smoke... Idk wat the problem is.. Help please

Asked by for the 1995 Chevrolet Tahoe
Is it a 2002 or a 1995 year model? Your post list it both ways!
2002 sorry about that