Yamaha FJR1300R, Service Manual

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GEN
INFO
FEATURES
FI SYSTEM
The fuel pump delivers fuel to the injector via the fuel filter. The pressure regulator maintains the
fuel pressure that is applied to the injector at only 2.55 kg/cm
2
higher than the intake manifold pres-
sure. Accordingly, when the energizing signal from the ECU energizes the injector, the fuel passage
opens, causing the fuel to be injected into the intake manifold only during the time the passage
remains open. Therefore, the longer the length of time the injector is energized (injection duration),
the greater the volume of fuel that is supplied. Conversely, the shorter the length of time the 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, crankshaft position sensor, intake air pressure sensor, atmospheric
pressure sensor, intake temperature sensor, coolant temperature sensor, and O
2
sensor enable the
ECU to determine the injection duration. The injection timing is determined through the signals from
the crankshaft position sensor and the cylinder identification 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.
1
Fuel pump
2
Pressure regulator
3
Fuel injector
4
Throttle body
5
Intake temperature
sensor
6
Throttle position sen-
sor
7
Intake air pressure
sensor
8
ECU
9
Atmospheric pressure
sensor
0
Coolant temperature
sensor
A
O
2
sensor
B
Cylinder identification
sensor
C
Crankshaft position
sensor
È
Fuel system
É
Air system
Ê
Control system
#4 #3 #2 #1
Illustration is for reference only.