Possible Fuel Pump Problem

I own 2000 grad prix GT, When im going highway speeds and a near floor the gas pedal the engine start cuttin out choppin hard and RPMS jump high then low it gets really un stable only at high speed this occurs...is that fuel pump...Cars runs flawless lower speeds.

Welcome to AF.

Your post has been moved to the regular part of the Grand Prix forum.

From the vague symptoms, my first thought was a sticking TCC solenoid not allowing the torque converter to unlock. To accurately help you, we will need more info, and doing a fuel pressure test wouldn't hurt to help rule out the fuel pump.