Hi, My car is a 1987 iroc z 350 tpi... I have a huge problem with power loss, more specifically when going around turns and stepping on the gas real hard the car just dies.. It doesnt shut off but its like it's starved for gas. The car idles ok when in park but switching to reverse or drive sometimes I have to put my foot on both the brake and gas just to keep it running. It has a new fuel filter, pump, plugs/wires,distributor cap... The car starts fine but real issues with what seems like a lack of gas when i step on it or go around turns...

Please help!
I'm not mechanically inclined at all.. All the work is done through a mechanic so please try and make your suggestions as easy to understand from a newbie point of view!

Thank you!