81 

Cooling liquid temperature sensor 
malfunction 

Air filter blocked 

Poor fuel quality 

Clean 

Replace 

Replace 

Tire obviously worn or pressure severely insufficient 

Clutch slipping 

Temperature control system malfunction 
causing large oil consumption 

Fuel pipe leaking 

Braking seizing 

Oil tank cover not well 
sealed 

Canister control non-return valve 
damaged 

Inlet pressure and temperature sensor damaged

 

Throttle valve position sensor with open 
circuit 

Repair or replace 

Replace 

Replace 

Replace 

Repair 

Repair 

Replace 

Replace 

Replace

 

Normal 

Open circuit

Normal 

Abnormal

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Damaged

Not well sealed

Seizing

Leaking

Abnormal

Slipping

Unusual

Poor

blocked

Abnormal

 
 

 

 

82 

 

Replace 

Individual cylinders not 
working 

Incorrect valve timing of the engine 

Cylinder pressure too low 

Idling speed too large or too small 

Water temperature abnormal l 

Three-way catalyzer blocked 

Repair 

Repair 

Repair 

Repair 

Repair 

Normal 

Abnormal

Normal 

Normal 

Normal 

Normal 

Abnormal

Too low

Incorrect 

Not working

Blocked

 
 

 

 

83 

 
No. 047 Intake tempering   

Malfunction Causes 

Solution 

 

Improper ignition timing 

Check ignition timing. When the engine is at idling speed, ignition advance angle 
is 10°--12°; if not correct, adjust advance angle of initial ignition of the engine. 
When accelerating, ignition advance angle could automatically be increased to 
20°--30°. If unusual, check ignition control system or replace ECU; 

Valve not well closed 

Check valve clearance is normal; if not, adjust it; if the valve is burnt and 
deformed and not well closed, replace the valve and re-furbish;   

Oil injector blocked or with 
poor atomization 

Remove oil injector; check ejecting amounts and atomization are normal; if not, 
clean or replace oil injector; 

Inlet pressure sensor 
malfunction 

Check intake manifold pressure temperature sensor; if unusual, replace it;   

Throttle valve position sensor 
malfunction 

Check throttle valve position sensor. When throttle valve is changed from fully 
closed to fully opened, resistance of its signal terminal and earthing terminal shall 
be increased continuously, without interruption; if unusual, adjust or replace it 
accordingly; 

Gas mixture too thin   

Oil duct malfunction is caused by too low oil ejected, which is caused mainly as: 
oil pressure is too low; oil injector blocked. Malfunction of intake system is 
caused as intake amounts are too many, which is caused mainly as: sensor 
controlling intake amounts are invalid; intake manifold leaking;   

Engine valve timing error   

Check valve timing is correct; if not, adjust it; 

Intake 
manifold with 
tempering  

Oil injection control program 
malfunction within ECU 

Replace engine’s Electronically Controlled Unit (ECU); 

 

 
 

 

 

84 

 

Check and adjust 

Replace 

Intake tempering 

Improper ignition timing 

Valve not well closed 

Oil ejector blocked or with poor 
atomization 

Inlet pressure sensor malfunction 

Throttle valve position sensor malfunction 

Gas mixture too thin 

Engine valve timing error 

Repair 

Replace 

Clean 

Repair 

Malfunction of oil injection control 
program within ECU 

Replace 

Repair 

Normal 

Abnormal

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Improper

Not well closed

Poor atomization

Abnormal

Unusual

Too thin 

Error