Chery SQR 7160 sedan. Manual — part 121

4.2 Hard to start

Check fault

codes

Determine fault source upon fault

codes

Check if air intake system

vacuum leakage or intake

valve dirt

1 Hose connection

2 throttle valve body air intake

valve

3 PCV hose

check if ignition system fault

1 wire

2 ignition coil

3 spark

1 Remove fuel injector

connector on each cylinder

2 keep the spark plug about 8mm

away from cylinder body. Start

motor and watch firing. A strong

fire should be visible

Watching firing of each cylinder and check spark and spark plug gap

Spark plug gap: 1mm

Note: If necessary, measure compression pressure and air valve gap

1 fuel injector leakage or short

2 fuel injector wire short

3 over fuel injection

Check fuel supply:

1 if fuel tank is empty

2 fuel supply pipe fuel pressure. When ignition key is

turned to ON position, the pump should operate 1~2

seconds.

Listening pump operating sound in fuel tank;

Feeling pressure in fuel return pipe.

1 fuel circuit leakage or

deformation

2 fuse

3 pump relay

4 fuel pump

5 fuel pump filter

6 fuel pressure

regulator

7 fuel injector

Check idle step motor

1 idle motor mount screw

2 when ignition is turned on, short

vibration should be felt.

1 replace or turn mount

screw

2 step motor connection

3 step motor

Check circuit

Using voltmeter or

oscilloscope

1circuit

connection

2 ECU voltage

Fusible link

Fuse

4.3 Rough Idle

Check fault code

determine fault source upon fault

code

Check air intake system

vacuum leakage, air intake

valve dirt

1 Hose connection

2 throttle valve body air intake

valve

3 intake manifold mounting

Check air filter core

Wash or replace

Check ignition system fault

1 check if wire power leakage

2 check if ignition coil breakage

or damage

1 check high-tension

wire

2 check ignition coil

Watch firing of each

cylinder and check spark

plug and spark plug gap

Plug gap: 8mm

NOTE: if necessary,

check compression

pressure and air valve

gap

1 replace spark plug

2 cylinder compression

pressure

3 air valve gap

Throttle valve position

sensor and connection,

repair or replace as

necessary

Check throttle valve position

sensor

Check step motor fault

1 check mounting

screw

2 short vibration

should be felt when

ignition turned on

1 measure step motor coil

resistance

2 check step motor wire

3 replace or turn idle motor

mounting screw

Check fuel circuit fuel

pressure

1 check fuel pressure regulator

2 check fuel pump

3 check fuel filter, repair or replace as

necessary

Check fuel injector

Check fuel injector, injector

dirt, and repair or replace as

necessary.

Check coolant temperature

sensor

Check coolant temperature

sensor and connector, repair or

replace as necessary

Check intake air

temperature pressure

sensor

Check intake air temperature

pressure sensor

Check oxygen sensor

Check oxygen sensor, And

replace if damaged.

4.4 High Idle Speed

Check fault

codes

Determine fault sources

upon diagnostic codes.

Check air intake

system

Vacuum leakage

1 hose connection

2 throttle valve body

intake air valve

3 intake manifold

installation

Check throttle

position sensor

Throttle position sensor

and connection, repair and

replace when necessary.

Check step

motor fault

1 check step motor coil

resistance

2 when warming up and

engine idle, use scan tester

to read step motor total

steps, and adjust the idle

screw till total steps is

20-40

Check coolant

temperature

sensor

Check coolant temperature

sensor and connecting

wire, repair or replace as

necessary.

Check fuel

pressure

Check pressure regulator,

and fuel pressurea, repair

or replace as necessary.

Check fuel

injector

fuel injector, repair or

replace as necessary.

4.5 Low idle speed

If engine idle speed is low referring to each actuator and sensor mentioned above, check

following components:

Engine coolant temperature sensor fault: check engine coolant temperature sensor and

wire, repair or replace as necessary.

Air intake temperature sensor fault: check air intake temperature sensor and wire,repair or

replace as necessary.

Step motor fault or stuck

Throttle position sensor fault: check engine throttle position sensor and wire, repair or

replace when necessary.

Fuel pressure and injector