Electronic Fuel Injection Control - Yamaha F225F Service Manual

TECH
FEA

Electronic fuel injection control

In electronic fuel injection control, the engine ECM determines the fuel injection timing and fuel
injection amount according to the signals from the sensors and performs the appropriate fuel injec-
tion. The fuel injection amount is controlled by the fuel injector actuation time. There are 2 types of
fuel injection timing control: synchronous fuel injection and asynchronous fuel injection. According
to the engine operating conditions during the control, the control mode switches automatically
between the start-up mode, normal operating mode, and fuel injection cutoff mode. In addition, vari-
ous compensations are made to determine the actual fuel injection timing and fuel injection amount.
Also, a fuel injector anti-sticking control has been adopted.
Pulser coil
Cam position sensor
(PORT EX)
Cam position sensor
(PORT IN)
Cam position sensor
(STBD IN)
TPS
SPS
LPS
Air pressure sensor
Air temperature sensor
Engine temperature sensor
Thermoswitch
Engine shut-off switch
Battery
2-5
Technical features and description
Engine
ECM
Fuel injector
High-pressure
fuel pump
Low-pressure fuel
pump
Vapor shut-off
valve