Fi System - Yamaha R1 Series 2015 Service Manual

FEATURES
EAS30617

FI SYSTEM

The fuel pump delivers fuel to the fuel injector via the fuel filter. The pressure regulator maintains the
fuel pressure that is applied to the fuel injector at a certain level. Accordingly, when the energizing signal
from the ECU energizes the fuel injector, the fuel passage opens, causing the fuel to be injected into
the intake manifold only during the time the passage remain open.
Therefore, the longer the length of time the fuel injector is energized (injection duration), the greater the
volume of fuel that is supplied. Conversely, the shorter the length of time the fuel injector is energized
(injection duration), the lesser the volume of fuel that is supplied.
The injection duration and the injection timing are controlled by the ECU. Signals that are input from the
throttle position sensor, accelerator position sensor, coolant temperature sensor, atmospheric pressure
sensor, cylinder identification sensor, IMU (Inertial Measurement Unit), crankshaft position sensor, in-
take air pressure sensor, intake air temperature sensor, rear wheel sensor and O sensor enable the
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ECU to determine the injection duration. The injection timing is determined through the signals from the
crankshaft position sensor. As a result, the volume of fuel that is required by the engine can be supplied
at all times in accordance with the driving conditions.
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