Denso CRS - Fuel Injection Control Strategies; Fuel Injection Control

Operation Section
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7. CONTROL SYSTEM
7.1 Fuel Injection Control
(1) General Description
• This system effects more appropriate control of the fuel injection quantity and injection timing than the mechanical
governor or timer used in the conventional injection pump. The engine ECU performs the necessary calculations
based on the signals that are received from the sensors located on the engine and the vehicle. Then, the ECU controls
the timing and duration of the current that is applied to the injectors in order to obtain optimal injection timing and
injection quantity.
(2) Various Types of Fuel Injection Controls
Control Functions
Fuel Injection Quantity Control This control replaces the function of the governor in the conventional injection
pump. It achieves optimal injection quantity by effecting control in accordance with
the engine speed and accelerator opening signals.
Fuel Injection Timing Control This control replaces the function of the timer in the conventional injection pump. It
achieves optimal injection timing by effecting control in accordance with the
engine speed and the injection quantity.
Fuel Injection Rate Control
(Pilot Injection Control)
This function controls the ratio of the fuel quantity that is injected from the orifice of
the injector within a given unit of time.
Fuel Injection Pressure Control This control uses the rail pressure sensor to measure the fuel pressure, and it
feeds this data to the engine ECU in order to control the pump discharge quantity.