Fi System - Yamaha YZFR6X(C) 2008 Service Manual

ET2C01019

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, 46.1 psi). Accordingly,
when the energizing signal from the ECU energizes the fuel injector, the fuel passage opens, caus-
ing 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 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 ener-
gized (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 (for throttle cable pulley), throttle position sensor (for throttle valves),
coolant temperature sensor, atmospheric pressure sensor, cylinder identification sensor, lean angle
sensor, crankshaft position sensor, intake air pressure sensor, air temperature sensor, speed sensor
and O sensor enable the ECU to determine the injection duration. The injection timing is deter-
2
mined 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 #2 #3 #4
20
19
18
1. Secondary injector
2. Fuel pump
3. Primary injector
4. Cylinder identification sensor
5. ECU (engine control unit)
6. Throttle position sensor (for throttle cable
pulley)
7. Throttle position sensor (for throttle valves)
8. Speed sensor
9. Air temperature sensor
10.Lean angle sensor
11.O sensor
2
12.Catalytic converter
A
2
#1 #2 #3 #4
1
3
16
B
17
15
1-3
6 7
C
10
5
13
4
11
14
13.Coolant temperature sensor
14.Crankshaft position sensor
15.Intake air pressure sensor
16.Throttle servo motor
17.Throttle body
18.Atmospheric pressure sensor
19.Air filter case
20.Intake funnel servo motor
A. Fuel system
B. Air system
C. Control system
FEATURES
8
9
12