Fuel Injection Compensation Control - Yamaha XV1700PCRC Service Manual

Fuel injection compensation control

• Starting injection control
The engine temperature is used for determining the injection duration in order to ensure proper start
ability. To suit the engine's operating conditions, the starting injection duration is determined by
applying a starting compensation coefficient to the basic injection duration, which forms the basis of
the injection duration.
(Starting injection duration = basic injection duration × injection compensation coefficient)
During starting, injection cylinder control is effected together with injection duration compensation.
The injectors of all cylinders inject only once immediately after receiving a signal from the crankshaft
position sensor during the cranking of the engine. This is called asynchronous injection, in contrast
to the synchronous injection, which is a normal cylinder injection that is effected on a cylinder-by-
cylinder basis.
After the asynchronous injection is completed, and until the ECU receives signals from the cylinder
identification sensor with the engine speed at 400 r/min or higher, the injectors are actuated in pairs
in sync with the signals from the crankshaft position sensor: cylinder #1 and cylinder #2. Controlling
both the injection duration and the injection cylinders in this manner enables a precise supply of fuel
in accordance with the starting conditions of the engine.
• Starting injection duration
È
Ê
0
É
3
• Starting cylinder control
È
É
1
Ê
É
2
Ê
1 Injector #1
2 Injector #2
3 Starting asynchronous injection
4 Identification of cylinder #1
5 Identification of cylinder #2
2
1
(˚C)
4
4 5
3
Ë
1 - 23
FEATURES
1 Basic injection duration
2 After-start compensation injection duration
3 Low
4 High
È Injection duration
É Engine temperature
Ê Extended duration
È Crankshaft position sensor
É Injection
Ê Stop
Ë Synchronous injection
GEN
INFO