Sequential injection system (SEFI)
The SEFI system uses electrical pulses of a strictly limited duration to control the injection of fuel through injectors directly into the intake port of each of the engine's combustion chambers. The moment and duration of opening of each of the injectors is controlled by the Power Control Module (PCM). The PCM continuously monitors various engine operating parameters and, based on the incoming information, determines the required volume of fuel injected into each of the intake ports. The throttle body in this case serves only to control the supply of air to the system. Due to the fact that each cylinder is equipped with its own injector, this system provides the ability to very accurately control the composition of the air-fuel mixture.
Fuel pump and fuel lines
Fuel is supplied from the gas tank to the injection system and its excess is returned back to the gas tank via two metal lines laid under the bottom of the car. The electric fuel pump is located inside the gas tank and is combined into a single assembly with the fuel consumption sensor unit. The fuel vapor return system carries out the removal of fuel vapors back to the gas tank via a separate return line.
PGM-FI Main Relay (fuel pump relay) equipped with primary and secondary electrical circuits. When the ignition is on, the primary circuit supplies power to the PCM, the injection injectors and to the secondary circuit of the relay, which in turn supplies power to the fuel pump. Power to the fuel pump lasts for two seconds when the ignition key is turned to the ON position and continuously when the engine is running.
Exhaust system
The exhaust system consists of an exhaust manifold, an upper flow manifold (before the catalytic converter) and downstream (after catalytic converter) oxygen sensors (l-probes), 3-function (reduction) catalytic converter, muffler and exhaust pipe.
The catalytic converter is one of the main components of the exhaust gas toxicity reduction system and is discussed in more detail in Chapter Engine management systems.
(The article was taken from the website: HondaBook.ru)