The fact that the fuel pump can cause the engine to surge is indication of a fundamental flaw in the TCM Continental fuel injection system. The fuel flow to the cylinders is controlled by the fuel pressure and the throttle position as well as the mixture knob. Why should the externally-applied fuel pressure affect the performance of the engine? It should not. The Lycoming injection system is controlled by the mass airflow into the engine and the mixture knob. Switching fuel pumps on and off does not affect the fuel/air ratio. This is the way it should be. the only responsibility of the fuel pumps should be to provide *enough* fuel. Not to regulate the pressure of the fuel and thereby control the fuel/air mixture.