1987 Pontiac Grand Am needs help

Black smoke means you're burning too much fuel.
You could have a leaky fuel injector, or a clogged air filter, defective fuel pressure regulator.

A residual fuel pressure test should tell you if your injectors or fuel pressure regulator are leaky.

Have you done a residual fuel pressure test (That involves hooking a pressure gauge to your fuel system, like at the fuel rail)?
If it drops, that would indicate a leak in your fuel delivery system, likely an injector or a pressure regulator.
That's what you need to do at this point. You may have a leaky o-ring on one/several of your injectors.

If the test is good, you need to check some of your sensors, like the O2 sensor. It's possible that one of them is messed up and doesn't send proper input to your pcm.

Also check your timing, and take a look at your spark plugs to make sure they're in good shape.