Yamaha FJR1300A(X), Service Manual

Page: 12 / 754

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, coolant temperature sensor, cylinder identification sensor, lean angle sensor,
crankshaft position sensor, intake air pressure sensor, intake 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 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.
1
15
14
B
13
12
11
10
9
A
2
3
8
4
C
6
5
7
#3 #1 #2 #4
1. Fuel pump
2. Injector
3. Cylinder identification sensor
4. ECU (engine control unit)
5. Throttle position sensor
6. Rear wheel sensor
7. Lean angle sensor
8. O
2
sensor
9. Catalytic converter
10. Coolant temperature sensor
11. Crankshaft position sensor
12. Intake air pressure sensor
13. Throttle body
14. Intake air temperature sensor
15. Air filter case
A. Fuel system
B. Air system
C. Control system