Yamaha FJR1300A(D), Service Manual

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FEATURES
1-3
ET3P61042
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 only 324 kPa (3.24 kg/cm², 47.0 psi). 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 remains open. There-
fore, the longer the length of time the fuel injector is energized (injection duration), the greater the vol-
ume 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, cylinder identification
sensor, lean angle sensor, crankshaft position sensor, intake air pressure sensor, atmospheric pres-
sure sensor, air temperature sensor, rear wheel sensor and O
2
sensor enable the ECU to determine
the injection duration. The injection timing is determined through the signals from the crankshaft posi-
tion 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.
#3 #1 #2 #4
1
17
B
15
16
14
3
13
A
2
4
12
5
C
9
6
10
11
7 8
1. Fuel pump
2. Injector
3. Coolant temperature sensor
4. Cylinder identification sensor
5. ECU (engine control unit)
6. Throttle position sensor
7. Accelerator position sensor
8. Atmospheric pressure sensor
9. Rear wheel sensor
10. Lean angle sensor
11. Air temperature sensor
12. O
2
sensor
13. Catalytic converter
14. Crankshaft position sensor
15. Throttle body
16. Intake air pressure sensor
17. Air filter case
A. Fuel system
B. Air system
C. Control system