Why does my Car cuts off when the gas pedal is pressed?

I have a1990 Oldsmobile Cutlass Supreme. Recently my car has started to act up. When I press the gas pedal, my car cuts off. When my car is in park, its fine. The problem is it cutting off when I press the gas pedal. I have recently had a tune up done, had all my fluids checked, added a new fuel pump, and a new throttle sensor. And its still doing the same thing. I dont know what else to do and Im losing money buying parts that I dont need. Can anyone PLEASE help??