Fi System - Yamaha N MAX GPD150-A 2015 Service Manual

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 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 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, crankshaft position sensor, intake air pressure
sensor, intake air temperature sensor, front wheel sensor and O
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.
16
1. Fuel pump
2. Fuel injector
3. Ignition coil
4. ECU (Engine Control Unit)
5. Front wheel sensor
6. ISC (Idle Speed Control) unit
7. O sensor
2
8. Catalytic converter
9. Coolant temperature sensor
10. Crankshaft position sensor
11. Throttle body
12. Throttle body sensor assembly
1
A
B
12
6
13
15
11
2
C
3
2
14
13. Intake air temperature sensor
14. Throttle position sensor
15. Intake air pressure sensor
16. Air filter case
A. Fuel system
B. Air system
C. Control system
1-3
FEATURES
sensor enable the ECU to determine
5
4 6
7
8
9
10