Hello I drive a 1995 Pontiac Grand Prix 3.1 se, 2 door coupe. When I accelerate my car it begins to jerk at 4000 RPM. I can't seem to figure it out and whenever I take it to a mechanic they can't seem to figure it out. Also whenever I reverse and turn my steering wheel all the way the car shuts off. Hope you guys can help me figure out these problems.