Fuel system
Fuel is pumped through a filter to each injector under pressure set by the fuel pressure regulator. Fuel is injected into the intake manifold in accordance with signals from the electronic control unit.
Air supply system
The air supply system provides the supply of the amount of air necessary for the operation of the engine.
The amount of air entering the engine is determined by the throttle opening angle and the engine speed. The air flow passes through the air filter, through the throttle body port, and into the top of the intake manifold, from where it is distributed to the engine cylinders. When the coolant temperature is low, the idle speed control valve opens and air enters the top of the intake manifold through the bypass in addition to the air passing through the throttle. Thus, even if the throttle valve is fully closed, air enters the top of the intake manifold, and therefore the idle speed increases. The top of the intake manifold reduces airflow pulsations.
Electronic control system
All engines are equipped with a HONDA electronic control system that controls fuel injection, ignition timing, diagnostic system, etc. using an electronic control unit. In this case, the following functions are performed:
1. Fuel injection control. Various sensors determine the air flow rate, engine speed, as well as the oxygen content in the exhaust gases, coolant temperature, intake air temperature, atmospheric pressure, etc., and convert the information received into an electrical signal sent to the electronic control unit:
Based on these signals, the electronic control unit determines the required amount of fuel and controls the injectors. The amount of fuel supplied is regulated by the duration of the raised position of the injector shut-off needle.
2. Ignition timing control.
The memory of the electronic control unit contains the values of the optimal ignition timing for all possible engine operating modes. Using the signals of various sensors that control the conditions of engine operation, the electronic control unit generates impulses that control sparking at strictly defined points in time.
3. Idle speed control system.
In the memory of the electronic control unit, the data of the optimal speed, idling, corresponding to various conditions (e.g. coolant temperature, air conditioner on/off, etc.). Sensor signals are sent to the electronic control unit, which controls the air flow through the bypass channel (besides the throttle) and regulates the idle speed in accordance with the specified value
4. Diagnostics.
The electronic control unit warns of a malfunction or abnormal operation by means of an indicator "MALFUNCTION INDICATOR LAMP" ("CHECK ENGINE") on the instrument panel. The fault is identified in the form of a diagnostic code, which is stored by the electronic control unit.
5. Function "Fail-Safe" ("Get home").
In the event of a sensor failure, emergency operation is provided (to get to the nearest service station). At the same time, the indicator on the instrument cluster lights up "MALFUNCTION INDICATOR LAMP".