Geely Diagnosis Flow. Manual part — 13

49

No. 029 Hard to stard engine when heating

Malfunction Cause

Solution

Check battery voltage, whether it is normal. If the value is
too low, shall charge and check charge circuit, as well as
related components.

Check starter, and maintain or replace it when starter coil is
heated and short circuit.

Low starter speed or sliding

If motor idles, then the starter flywheel gear and motor gear
slide when match, which results engine hard to start.

Electric controlling system
malfunction

Connect Geely special decoder to check whether there is
malfunction code. And inspect again if it shows malfunction
code. Then check relevant component and circuit according
to the indication of malfunction code.

Spark plug malfunction

Check spark plug electrode clearance and carbon deposit
condition. Adjust or replace it when necessary.

Check heating operation, whether there is high voltage
spark. If not, check engine speed sensor, ignition coil, ECU
and relating circuit. Maintain or replace them when
necessary.

Weak high voltage spark

Check high voltage spark energy. If it is weak, check ignition
coil, spark wire resistance. Replace them when abnormal.

Cooling fluid temperature sensor
malfunction

Check cooling fluid temperature sensor. In different
temperatures, its resistance shall vary according to specified
standard. Replace it when necessary.

Injector malfunction

When heating, the expansion difference of valve seat and
element may affect injector pin valve and result valve
seat and element stuck or leak, which relates with spark
plug drown and primary fuel pressure lose and cause hardly
to ignite. Check injector, replace it when necessary.

Fuel quality problem

Check fuel, whether it is polluted, or contains other problem.
It is recommended that customers shall change the gas
station, where they often attend.

Engine cylinder, connect rod,
crankshaft and camshaft bearing fit
pressure is over normal value

Engine cylinder, connect rod, crankshaft and camshaft
bearing fit pressure is over normal value, the expansion
when heating will result crankshaft stuck. Maintain relating
part.

Speed sensor output signal abnormal

Engine speed sensor resistance or output signal and signal
tooth clearance abnormal, which results improper ECU
ignition timing, as well as engine hard to start. Shall adjust or
replace engine speed sensor.

Air filter blocked

Clean or replace

Low fuel pressure

Check fuel pressure, if it is too low, shall inspect fuel
pressure controller, electric fuel pump, fuel filter and pipes.

Intake pressure temperature sensor
operates abnormally

Intake pressure temperature sensor is heated, which results
signal misalignment.

Hard to start engine
when heating

ECU inner malfunction

The triode in ECU controller is heated, and fails to input or
output signal normally. Shall replace ECU.

50

Intake pressure temperature sensor operates

abnormally

ECU inner malfunction

Low fuel pressure

Air filter blocked

Speed sensor output signal abnormal

Engine fit pressure is over normal value

Fuel quality problem

Injector failure

Cooling fluid temperature sensor failure

Weak high voltage spark

Spark plug failure

Electric controlling system failure

Low starter speed or sliding

Hard to stard engine when heating

Replace

Check and replace

Clean

Check

Check

Check

Check and replace

Replace

Clean and replace

Replace

Replace

Replace

Replace

Blocked

Low

Lack

Abnormal

Abnormal

Abnormal

Abnormal

Over fitted

Abnormal

Abnormal

Abnormal

Abnormal

Abnormal

Normal

Normal

Normal

Normal

Normal

Normal

Normal

Normal

Normal

Normal

Normal

Normal

51

No. 030 Idle speed unstable

Malfunction Cause

Solution

Improper throttle position sensor
adjustment

When idling, the action, such as open AC, operate steering wheel
or open front lamp, will increase engine load. ECU will add
injection quantity to remain engine running stably, as well as to
prevent engine shut-off when engine load increased. Disconnect
idle speed conducting point, while engine is not running in idle
condition, determined by ECU, and it will remain injection quantity
instead of increase it. Therefore, the engine speed remains as
before, and ECU will adjust idle speed according to the order of
oxygen sensor mixer. The malfunction is indicated by low engine
speed when open AC or operate steering wheel in idle condition.
When the throttle is closed totally, inspect idle switch of throttle
position sensor by Geely special deNo.r, whether it is normal.
Adjust or replace it when necessary.

Idle speed by-pass pipe blocked

Check throttle and idle speed by-pass pipe, whether they are
blocked. Clean it when necessary to ensure free-flowing air
intake.

Idle speed control valve or
stepping motor malfunction

According to engine speed, temperature, throttle open degree
and AC signal etc., ECU will calculate and adjust idle speed
control valve or stepping motor, as well as by-pass pipe, to
decrease engine speed. If idle speed control valve delayed or
stuck, as well as in the case of throttle malposition etc., ECU will
fail to implement idle speed adjusting correctly, which results idle
speed unstable. Shall clean or replace relating parts, sc. replace
idle speed control valve and implement self-adaption on idle
speed control valve or stepping motor by deNo.r, series Geely,
when necessary.

Electric controlling system
malfunction

Connect Geely special decoder to check whether there is
malfunction code. And inspect again if it shows malfunction code.
Then check relevant component and circuit according to the
indication of malfunction code.

Engine idle speed
unstable

Individual cylinder fails to work

Check operating condition of each cylinder, whether there is
individual cylinder, which operating abnormal. Particularly the
spark plug, spark wire, cylinder pressure etc. Maintain or replace
then when malfunction cause was found.

52

Intake pipe leak

Intake pipe leaking and results incorrect flow rate decision on
ECU, which will cause unstable idle speed. Check leaking
position, particularly intake manifold gasket, injector seal ring,
vacuum pipe and connector etc.

It has not implement
self-adaption, after engine ECU
or battery was replaced.

In case of replacing engine ECU, battery or disconnect battery
power for a long time, it shall implement self-adaption according
to Geely engine self-adaption procedure.

Generator voltage abnormal

Check running engine, whether the output voltage of generator is
in normal value. If it is abnormal and results unstable idle speed,
then check generator and relating circuit and parts. Maintain or
replace them when necessary.

Injector leak or block

If the injector is leaking or blocked, and fails to inject according to
ECU order, which results improper mixure gas viscosity, as well
as individual cylinder operating abnormal and unstable idle
speed, then shall replace the injector.

Exhaust system blocked

Gum deposit, carbon deposit, broken or such problems in 3-way
catalytic converter result partly or random blockage, which will
increase the backpressure when exhausting, as well as low
vacuum of intake pipe, which results abnormal engine exhaust
and intake performance, that relating with cylinder operating
performance directly. Replace 3-way catalytic converter.

Improper stepping motor gasket
thickness

Often appears on vehicle MR7131A, stepping motor gasket is too
thin caused by manufacture process, and results motor operating
abnormal. Exclude the malfunction by replacing gasket.

Intake temperature sensor
malfunction

Check sensor data and voltage, replace it when necessary.

Low fuel pressure

Measure fuel pressure, check electric fuel pump, pipes and circuit
when it is lower than normal value. Maintain or replace them when
necessary.

Improper spark plug and ignition
advance angle, which results
unstable idle speed

Check spark wire cross firing condition, as well as ignition timing.
Adjust or replace it when necessary.

Engine bracket cracked

Check vehicle, whether there is any sign of accident. Engine
bracket cracked will cause engine vibration, and unstable idle
speed.

Oxygen sensor malfunction

Check oxygen sensor signal, replace it when necessary.

Canister valve malfunction

Check canister control valve, replace it when necessary.