Chery SQR 7160 sedan. Manual — part 40
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1. fuel tank
2. fuel pump
3. fuel
filter
4. check valve
5. fuel pressure regulator
6. fuel
injector
7. air filter
8. fuel vapor connecting pipe
9.engine
idle
speed
actuator
10. absolute pressure sensor 11. injection/ignition system ECU
12. throttle valve position sensor 13. water sensor
14. intake temperature
sensor
15. injection/ignition system dual relay 16. ignition coil
17. tacho / TDC sensor
18. spark plug 19. CHECK-UP1
diagnostic port
20. fuel vapor recirculation solenoid 21. λsensor
22. tachometer
23. IAW system warning indicator
Two. Operation principle:
Single Port Injection System is applied on the vehicle equipped with 3 way catalyst converter .the
system insures air/fuel mixture ratio in the vicinity of the ideal air/fuel ratio.
The ideal air/fuel ratio is important for catalyst converter to work normally. The aim having the catalyst
converter installed is to reduce harmful exhaust emission. Theλsensor, analyzing oxygen content in exhaust
gas continuously , may ensure getting ideal mixture . If air/fuel ration is not ideal, ECU may adjust the mixture
consistence continuously by measuring fuel intake in progression.
Fuel system(fuel pump, fuel filter, pressure regulator) offers the fuel of 1 bar to fuel injector.
The fuel Injection value is proportional to the air sucked into the engine . also the fuel is injected into
intake manifold synchronously with TDC . under some specified condition , the amount of fuel needed for
engine circulation is too small to measure, the system may perform a asynchronous injection ( inject once
instead of the normal injection ever several TDCs ).
Ignition controller with inductive discharging is of electrostatic discharge type(distributorless). Ignition
Fig. 134 single port injection system
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advance is calculated by a basic chart(pressure, revolution) and trimmed by engine load, water temperature,
and air temperature. In addition, it may perform dynamic ignition advance to stabilize idle speed. Engine idle
speed actuator adjusts the by-pass pipe opening to keep idle value constant . And engine idle actuator is
consisted of linear stepper motor.
Generally, ECU receives input signal and operates output actuating device to integrate idle speed, spray,
ignition’s control. Moreover, HCMOS microprocessor, with wonderful static-prevention and high-speed
calculation ability and low power consumption, may fulfill the following functions:
· the diagnosis for resuming system operation. As a sensor fails, the diagnosis system may resumes the
operation using the stored value preset..
·diagnosis for faulty Actuator condition
·Even if stopped, as a system part fails , the
warning indicator will be energized and the
information of fail type will be stored.
·during service, diagnostic tester may be connected and actuator may be operated to check for failure.
1.“I.A.W 6F. ”ECU
Read the square figure (figure 135), ECU processes all sensor signals related with running parameters:
·Intake manifold absolute pressure
·The TDC and revolution of cylinder 1,4 and 2,3
·Throttle valve open position
·Intake air temperature
·Engine coolant temperature
· A/C compressor switch signal
·Oxygen (λ) sensor signal (millivolt signal )
By this way, calculate air charge (process absolute pressure, air temperature, speed, and throttle valve position
signal) and use output circuit to control the following:
·control fuel injector switch on time for calculating fuel feed.
·control by-pass air volume and ignition advance for stepper motor compensating to control idle
speed.
·control two high pressure ignition coil, and ignition energy of cylinder 1,4 and 2,3.
·control fuel vapor recirculation solenoid switch on/off
also ECU features a complete self diagnostic for input sensor and output actuator. The diagnosis may be
performed by connecting CHE CK—UP1 with system and the failures detected will be shown on the screen.
For instance:
·all sensor are shorted or opened, including pressure, air, water, throttle valve, λsensor, TDC/RPM sensor
( signal sequence is missing).
·Engine idle speed actuator (stepper motor) doesn’t work.
·stepper motor, fuel injector, and fuel pump circuits are shorted
·high pressure ignition coil, fuel vapor recirculation solenoid is shorted or opened.
main parameters are shown according to the requirements: speed, water temperature, injection time,
ignition advance , intake manifold pressure, throttle valve position, battery voltage, stepper motor
position(steps).
when engine is stopped and ignition switch is on, ECU may perform active diagnostic function, which
may operate ECU microprocessor to check whether the following accessories are running well or not: fuel
pump, fuel injector, and fuel vapor recirculation solenoid. After service, you may erase trouble code stored. To
check stepper motor, technician needs to start the engine before checking.
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Throttle valve position sensor
TDC/RPM sensor
Absolute pressure sensor
High pressure ignition coil
Oil injector
Fuel pump
Engine idle actuator
Fuel vapor recirculate
solenoid
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According toλsensor signal, ECU will automatically revise C0 parameter(close loop). When λsensor
fails, ECU may work under open loop.
2. Single Port Injection System Throttle Valve “30MM12”
“30MM12” throttle valve is one of the main system parts. Most sensors and actuators are assembled in the
throttle valve. Throttle valve features small accessories, compact structure, and an bran-new inner geometry
structure to better the fuel atomization from fuel injector and get the most proper mixture for optimizing
engine performance. Throttle valve is installed on intake manifold.
Throttle valve casting are consisted of upper and lower bodies. Upper body(cap) is for arranging fuel
passages, and the lower body is for controlling engine air intake volume. Fig. 136 indicates the throttle valve
structure.
2.1 Upper body(fuel system)— description and function of accessories
λ sensor
A/C signal
Intake temperature sensor
Water temperature sensor
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Fig. 135 The control-illustration for single Port Injection System
Pressure adjuster
intake temperature sensor
oil injector
Upper body
fuel intake
hot water connector
recirculate solenoid
Lower body
Fig. 136 throttle valve structure
throttle valve position sensor
idle actuator
hot water connector
return fuel valve
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