2002 Chevy Malibu 3

2002 Chevy Malibu 3.1L Engine was replaced with a 34000 mile 3.1L Engine. The acceleration was slow, similar to a 4 cylinder. The belt shred and had to be replaced. The problem seemed to be a loose/malfunctioning pulley. The pulley was replaced and the power was regained. That same day, 7 days after the engine was replaced, the car stalled at acceleration. The problem was said to be air in the gas. Lucas gas treatment was used in conjunction with the gas cap being replaced. The problem started to take shape. The stalling continued accelerating during turns and stops also stuttering and possibly shutting off after going over bumps and up hills. Bridges take the car out. At these times putting the car in neutral and trying to restart it does not work. During cut offs over bumps on flat terrain at speeds over 40 the car may be restarted in neutral. If the speed is real low the distance needed to travel while in control of steering the car is not great enough. The problem was said to be the fuel pump. The fuel pump was replaced and the problem still exists. The mechanic that put the engine in, re checked the connections (wires and mounts) and said all is fine. Oh, the reading on the check engine scan machine said that it was the tork catalytic syllinoid. Upon research, I found that this issue Tork Catalytic Syllinoid issue could be a broken motor mount that is allowing fuel to get into the carburetor and choking the engine. This is a big issue and I don't want to have to have my transmission checked or worked on if something in this "new" engine is causing my car to cut off fuel supply in order to stop issues with explosions. Also upon neutral starts 2 times I smelled smoke.