CAC Gasoline Engine Maintenance And Servicing Manual
83
IWM523 fuel injector applied in the system is of the shortened type of the first generation. It is entirely
made of stainless steel and superior in the function. The advantage may be embodied when the commercial
fuel containing corrosive material is applied. figure 138 shows fuel injector structure and some technical
parameters.
Technical parameters:
－winding resistance
R=1.8Ω+/-10%(20℃)
－power supply voltage
V=6-16V
－spraying shape
angle 30～90°
－operating temperature
-30～+110℃.
when fuel injector is not operating, it is sealed and doesn’t allow fuel drain. Fuel needed by engine, is
controlled by ECU(supplied electricity by relay (87))directly. And ECU decides the open time of each intake
order and fuel injection duration.
Fuel injection time is controlled by the following measures:
-synchronous(for normal operation) .injector opening corresponds with every TDC.
-not synchronous (for idling, cut-off, low speed, start operation).injector opening is completely
controlled by time and not related to TDC signal.
ECU has a basic current control circuit to control fuel injector. The circuit produces the maximal
current(signal) at the first control order speed up the opening of injector. Once maximum current is attained ,
the circuit will automatically change to and keep the current I=1A±0.3 A(Mean).
Injection duration is showed on the 2-dimension figure as a function of engine speed and intake manifold
absolute pressure . After engine warming up or speed turns to be stable, injection duration is 1～4mS.
Injection duration is increasing basically under special operation condition, such as accelerating, cold
starting, engine warming up. As accelerator pedal is released, fuel will be cut off.( ti=0mS). Running condition
and readjusting condition may be changed according to water/ intake air temperature or A/C condition.
——intake air temperature sensor “ATS05”
It is consisted of N.T.C.(Negative Temperature Coefficient) thermo resistance and 2-way junction box that
are installed in the plastic setting molding case. Sensor resistance will changed with intake air temperature.
Fig. 138 fuel injector
+12V relay
ECU 18 insert pin
PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.com.cn
To Next Page
Loading...
