FOUR VALVES PER CYLINDER Four valves per cylinder are mostly used on DOHC (Double Overhead Camshaft) engines. Two of the valves are for the air-fuel mixture intake while the other two open to allow the exhaust gases out of each cylinder. Fire Prevention System FPS The Fire Prevention System (FPS) is designed to interrupt fuel delivery in the event of a collision, thus minimizing the risk of fire. Fuel cutoff FUEL CUTOFF A computer-controlled shutoff to the fuel system designed to prevent drivers from over-revving the engine, since over-revving is a primary cause of engine failure. Fuel Injection FUEL INJECTION Fuel injection is a mechanical or electronic system designed to inject atomized fuel directly into the cylinders of an internal-combustion engine. Essentially, it replaces the carburetor by being much more efficient, since the injection process is much better controlled. Fr...