DIRECT FUEL INJECTION SYSTEM [SKYACTIV-G 2.0]

2016 – MX-5 – Engine

The direct fuel injection system injects high pressure fuel directly into the combustion chamber using multi-hole injectors. Atomized fuel injected from multiple holes facilitates vaporization and the air temperature in the combustion chamber decreases. Due to this, anti-knocking performance has been improved for an improved high compression ratio and engine output.
High response has been achieved because there is no time lag from when the fuel injection starts until the fuel is provided to the combustion chamber.

Part name	Reference
High pressure fuel pump	(See HIGH PRESSURE FUEL PUMP [SKYACTIV-G 2.0].)
Fuel injector	(See FUEL INJECTOR [SKYACTIV-G 2.0].)
Fuel distributor	(See FUEL DISTRIBUTOR [SKYACTIV-G 2.0].)
Fuel pressure sensor	(See FUEL PRESSURE SENSOR [SKYACTIV-G 2.0].)
Spill valve control solenoid valve	―
Relief valve	―

Fuel from the high pressure fuel pump is injected directly into the cylinder by the fuel injector via the fuel distributor. There are two injection timings: Case (1) where injection occurs during the intake stroke, and case (2) where injection occurs during the compression stroke. The PCM performs control according to the input signal from each sensor. Injected fuel during the intake stroke is diffused uniformly in the combustion chamber by the flow of intake air, achieving a uniform air-fuel mixture. Fuel during the compression stroke achieves an air-fuel mixture required for combustion around the spark plug. For the fuel injection control, refer to the [CONTROL SYSTEM]. (See FUEL INJECTION CONTROL SYSTEM [SKYACTIV-G 2.0].)

The fuel pressure sensor detects the fuel pressure in the fuel distributor and sends a fuel pressure signal to the PCM. Based on the signal from the fuel pressure sensor, the PCM controls the high pressure fuel pump so that the fuel pressure is in accordance with the driving conditions. For the high pressure fuel pump control, refer to the [CONTROL SYSTEM]. (See HIGH PRESSURE FUEL PUMP CONTROL [SKYACTIV-G 2.0].)

Fuel pressure is adjusted by the spill valve control solenoid valve, and a relief valve in the high pressure fuel pump is equipped to ensure safety in case of a malfunction. When the fuel pressure exceeds the specified value, the relief valve opens to prevent the fuel pressure from increasing. For details on the high pressure fuel pump, refer to the [HIGH PRESSURE FUEL PUMP] for the fuel system. (See HIGH PRESSURE FUEL PUMP [SKYACTIV-G 2.0].)