WaynesIroc

I'm having some problems with the drivetrain in my 89 IROC-Z. Ever since I've owned the car I hear a fluttering noise when accelerating or trying to power brake. It only does it in the driving gears(reverse,OD,D,2,1) and not in nuetral or park. I'm thinking it is the torque converter but am not sure. It only does this under heavy acceleration. I don't think I'm getting all the power to the wheels I should either. Is the torqe converter my problem.