Chery SQR 7160 sedan. Manual — part 125

(1) Fuel pump

Fuel pump is located in the fuel tank with a mesh filter on pump inlet. The rotor is
driven by motor whose power is supplied by relay. A pressure relief valve is installed on
pump, which cut off fuel supply and suction to avoid motor overheat when pipe pressure is
above 7 bar. Pump operates under fuel temperature is within -30℃～+70℃ and normal
flow rate is 90L/Hr under 12 voltage.

ECU control pump through relay as followings:

－When ignition key is turned on for 2 seconds, engine off, pump start to operate;

－When engine is operatingand vehicle is running , pump operates continuously;

－When engine speed is lower than a specified value (about 50rpm), pump stops
operating.

(2) Fuel pressure regulatorFuel pressure regulator is inside the fuel tank, calibrated at

3.5bar fixed pressure.

(3) Fuel filter

Fuel filter is located outside of fuel tank. The fuel filter consists of housing and low

filter core of high filtering quality. Due to fuel injector is excessively sensitiveto foreign

materials in fuel feed circuit, fuel filter is a necessary part to engine’s normal operating.

Note：Arrowhead is marked on the housing of fuel filter, indicating the flowing direction

of gasoline. During installing, fuel filter is not allowed to install in a reverse direction.

Otherwise, the fuel filter must be replaced with a new one.

Replace fuel filter every 2000-3000km.

(4) Quick coupler

The fuel pump inlet and outlet is connected to fuel pipe

via a quick coupler, red quick coupler connects to outlet and

white quick coupler connects to inlet.

Removing quick coupler as shown in Fig 3.

* Hold the seat collar, push fuel pipe inward as arrow

Pressure regulator

1. fuel pipe 2. fuel return pipe 3.fuel tank 4.fuel filter 5.fuel pump 6.fuel injector 7.

Fig.2 Oil Supply System

Fig3 Quick Coupler Removing

direction, loosen fuel pipe.

* Hold seat collar firmly, pull fuel pipe off as arrow direction.

(5) Fuel rail

Fuel rail is used for distributing fuel into fuel injector and fixing fuel injector.

(6) Fuel injector

This system uses top fuel supply single hole fuel injector. Fuel injection pressure is 3.5bar，

output fuel is continuously atomized and in cone angle (15°angle from fuel injector axes )。

The control logic of fuel injector is: phase, sequence control. Four fuel injectors is controlled

according to four cylinders air intake sequence, opening in power stroke till intake stroke start.

Fuel injectors are fixed on fuel rail. Fuel rail press injector onto the fixed seat of intake

manifold, and is sealed by 2 O-rings.

1.upper O-ring 2.lower O-ring 3. fuel inlet 4.coil 5.wire terminal 6.electrical

connector

Fig4 Fuel Injector Diagram

2. Air system

Air intake system mainly consists of air filter, intake hose, intake manifold, idle step

motor and throttle valve body of throttle position sensor.

(1) Throttle valve body

Throttle valve body calculate air intake volume upon throttle pedal depressing status. Auxiliary

air intake volume is regulated by step motor when engine idles.

To avoid condensation and freezing under some conditions, throttle valve regulator bar

is against anti-stuck screw preventing throttle from full closed. . The anti-stuck screw is

adjusted during throttle valve body calibrating by manufacturer and do not turn the screw.

Fig 5 Outside Drawing of Throttle valve

1. throttle cable coil 2. Anti-stuck Screw 3.step motor 4.throttle position sensor

(2) Idle step motor

Idle step motor is used for controlling

idle speed ,directly fixed on throttle valve

body consists of one step motor and

screw/worm retard unit which change the

rotational movement of locking pin to linear

movement. After receiving control

command of ECU, step motor axially

moves valve spindle (about 0.04mm/step)

using screw/worm unit , by which change

by-pass air charge volume when engine

idles to control idle speed.

When temperature is at 20 ℃ , coil

resistance is R=53±10Ω. The maximum

air charge is achieved through backing 200

steps of locking valve. The amounts of

working step is determined upon engine operating conditions including warming up, A/C on

etc.

Fig 6 Idle Control Valve Operation Theory

1.Step motor 2. control valve 3.by-pass hole

4.throttle valve

3. Control system

(1) ECU

ECU is located in the cabin of engine, connected to wiring harness via 80-pin interface.

ECU is used for handling signals from various sensors and controlling actuators to obtain

optimum operating conditions..

Comparing to the previous mode, it has added many functions. But due to using of

many customized circuits of special functions, it has powerful integration, compact structure,

and small size.

ECU handle following signals:

- battery voltage;

-intake manifold absolute pressure ；

-Top Dead Center；

-throttle position；

-air intake temperature；

-Engine coolant temperature；

-A/C operation；

-oxygen sensor signal；

-knocking sensor signal。

Air charge efficiency is calculated upon managed intake manifold absolute pressure,

intake air temperature, engine speed and throttle position, by which air charge volume in

cylinder is obtained.

ECU controlsas below:

- Control fuel injection by controlling open time of fuel injector；

-Idle step motor；

-Four high voltage output ignition coil；

-carbon canister solenoid；

-A/C compressor；

- Warning indicator

Besides those functions, ECU can also controls：

-all self-diagnostics strategies on input sensors

and output actuators；

-“Wrong” signal recovery strategy on basic valid input signal；

Fig 7. Throttle valve position

sensor

A. Voltage positive B. ground C.

-Engine anti-theft function

(2) Throttle position sensor

Throttle position sensor is used for measuring throttle opening, determining idle, full