It is extremely dangerous to operate a vehicle with a bad fuel pump. A faulty pump could cause an unexpected loss of power or even completely shut down your vehicle. If these occur while you are on the highway, your car becomes a significant danger to other drivers. A bad fuel pump might also cause the engine to overheat. When this happens, the pump will incorrectly deliver gas to the engine. It might turn off while you are on the road. In such a situation, you must pull over to the side of the road and wait for help.