A puff of dark smoke on an aggressive throttle application is perfectly normal, particularly for a car that is primarily city-driven. That dark "smoke" is actually carbon dust and soot which builds up in the tailpipes and mufflers with low-speed running. You punch it, exhaust gas flow increases dramatically, and the nasties let loose.
Now.........back in the carburetor days, if you got a puff of black smoke on a sudden WOT, it was from the carburetor accelerator pump shooting a squirt of raw gas into the primary bores. A bit of tuning would get the pump stroke to the proper 'squirt". No way on a computer controlled SFI/MPFI (Sequential Fuel Injection/MultiPort Fuel Injection) setup. That takes a computer program and study to change injector timing and pulse rate.