Fi System - Yamaha FZ1-N Service Manual

ET2D1001

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/cm
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 remain 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, crankshaft position sensor, intake air pressure sensor, air temperature
sensor, coolant temperature sensor, speed sensor and O
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.
Illustration is for reference only.
1. Fuel pump
2. Fuel injector
3. Ignition coil
4. ECU (engine control unit)
5. Intake air temperature sensor
6. Throttle position sensor
7. Sub-throttle position sensor
8. O sensor
2
9. Catalytic converter
10.Coolant temperature sensor
11.Crankshaft position sensor
12.Intake air pressure sensor
sensor enable the ECU to determine the
2
13.Throttle body
14.Air filter case
A. Fuel system
B. Air system
C. Control system
1-3
FI SYSTEM
2
, 46.1 psi). Accordingly,