Hesitation

What causes my 82 Vette, that has just received a complete tune-up including, plugs, wires, diverter valves, rotor, ignition cap, ignition wires, map sensor, hesitate, falter and then regain power when I stomp on the accelerator. It is very dangerous. The car has a new fuel filter and a replaced fuel pump.

I’m putting half of your money on the throttle position sensor (tps), and the other half on the idle air control valve. The air passages to both should be cleaned with throttle body cleaner.
Go to www.autozone.com, and register, come back here and click on this link to their article on the tps: http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?partName=Throttle+Position++TP++Sensor&pageId=0900c1528003bb42&partId=0900c1528003bb42