118
·
Under the starting condition , the solenoid keeps close preventing the fuel vapor from richening the
mixture until the specified engine coolant temperature is reached.
·
during engine’s running, ECU sends a square wave signal to the solenoid. The signal is used to
control the fuel vapor recirculation valve by energizing or deenergizing it. By this way, ECU controls the
fuel vapor volume to intake manifold preventing the mixture density from changing dramatically.
·
under a specified working condition
：
——The throttle valve is at idling position
——Speed is lower than the specified
——The solenoid does not function When the intake pipe pressure is lower/ higher than the specified
value, the solenoid remains close to improve the engine performance.
—— Fuel cut-off switch The switch is located in the right side of driver. It will cut off the fuel supply
for the injection system by switching off the ground wire for fuel pump.
Fig.179
The steel ball, which is installed in the cone seat, is generally locked by the neighboring magnet
attraction. Under the specified accelerating load, the steel ball is released from the magnetism stillness and
begins to move up the cone seat with the travel of the movement depending on the cone angle.
A quick-release mechanism exists on the top of the ball. The mechanism circuit is closed under the
normal condition. When the mechanism is stricken by the ball resulting in the position variation, it will
vary from the closed circuit (NC) to the opened circuit (NO) and cut off the ground wire of fuel pump
simultaneously.
For the impact from any direction of the three vertical directions, the switch will fuction under
the condition of more than the peak value: 12g which is equivalent to the working condition of
25km/h or so. The switch may be reset by pressing the reset button. The reset button is protected
by a flexible cover (protecting the button from the influence from the external material and from
the necessity of resetting). Warning: Touching the surface lightly. If fuel is smelt or fuel system
leaking is present, do not turn on the switch. The leaking area should be located first and
recovered avoiding firing. If leaking does not exist on the surface, it may be restarted. Press the
button to restart the fuel pump.
