Fuel Control
Fuel is injected into the intake manifold, near the intake valve in precise metered amounts through electrically operated fuel injectors. The injectors are fired in a specific sequence by the engine Electronic Control Unit (ECU). The fuel rail supplies fuel to the injectors and is mounted to the intake manifold. Constant fuel pressure is kept in the fuel rail by a vacuum operated fuel pressure regulator mounted on the output end of the fuel rail. See Fig 1 .