29 

 

No. 016 Distributor oil leaking   

Malfunction Cause 

Solution 

Too much oil 

Drain spare oil 

Poor crankcase venting 

Check crankcase intake pipe, whether it is blocked. 
Clean and unplug intake pipe to exclude the malfunction.

Distributor seal ring ageing and damage 

Check distributor seal ring, whether it is ageing or 
damaged. Replace O-ring when necessary. 

High inner engine pressure 

Check exhaust pipe and single check valve, whether 
they are blocked. Unplug or replace them when 
necessary. 

Distributor rotating shaft loose 

Check distributor rotating shaft, whether the loose 
volume is in accordance with standard. Replace 
distributor assembly when necessary. 

Distributor rotor gear wearing 

Check distributor gear, whether it is worn out. Replace 
distributor assembly when necessary. 

Engine stands 
stil after 
activated. 
There is 
visible oil 
leaking at 
distributor 

Blow hole or crack on distributor 

Check oil leak of distributor sear and further determine the 
processing accuracy of distributor. If there is blow hole or 
crack, then shall replace distributor seat. 

 

 

Distributor oil leaking 

Too much oil   

Poor crankcase venting

High inner engine pressure

Distributor seal ring ageing and damage 

Distributor rotating shaft loose 

Distributor rotor gear wearing 

Blow hole or crack on distributor 

Drain spare oil 

Check 

Replace 

Replace 

Replace 

Check 

Replace 

Poor 

Over normal value 

Wearing 

Loose 

Loose 

Damage 

Y   

Normal 

Normal 

Normal 

Normal 

Normal 

N 

 
 

 

 

30 

 

No. 017 JL376/378 engine shut-off when sliding at neutral gear   

Malfunction Cause 

Solution 

Improper spark plag electrode 
clearance or spark plug current 
leak and non-resistance 

Adjust or replace spark plug (spark plug clearance is 1.0~1.1mm) 

Improper valve clearance 
adjustment 

Adjust valve clearance, 0.20±0.05mm in hot condition, 0.12±0.05mm 
in cold condition 

Distributor malfunction 

Maintain and replace distributor assembly 

Intake system leaking 

Maintain or replace relevant component； 

Idle speed controller (stepping 
motor) malfunction 

Check stepping motor controlling wire, resistance and blocked. Clean 
and replace then when necessary. 

Crankcase generates negative 
pressure 

Check exhaust single check valve 

Fuel circuit stuck (when steering) 

Maintain fuel tank, whether there is impurity in it. 

Fuel pressure abnormal 

When fuel pipe is leaking, replace it When air filter is blocked, replace 
it. When fuel pump or fuel pressure controller, which value shall 
between 264kPa and 305kPa, is damaged, replace it. 

Fuel contains in canister 

Maintain and replace canister 

Fuel contains in vacuum pipe 

Maintain oil pressure controller 

Throttle shaft run-out 

Replace throttle body assembly 

Wire malfunction 

Check wire circuit, whether it is poor contact. 

Engine operates 
well when 
accelerating 
normally, while 
shut-off when 
sliding at neutral 
gear or steering. 

Low cylinder pressure 

Check cylinder pressure, whether the valve is leaking, as well as the 
wearing condition of piston ring and cylinder. 

 

 
 

 

 

31 

 

JL376/378

 engine shut-off when sliding at neutral gear

Improper spark plug and valve clearance 

adjustment 

Fuel circuit stuck (when steering) 

Idle speed controller (stepping motor) 

Fuel pressure abnormal 

Distributor failure 

Intake system leaking 

Fuel contains in vaccum pipe 

Low cylinder pressure 

Adjust 

Maintain 

Check 

Clean and replace 

Maintain 

Check 

Replace 

Check 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Low 

Fuel contains 

Leak 

Stuck 

Improper 

Abnormal 

Abnormal 

Abnormal 

 
 

 

 

32 

 

No. 018 High idle speed when sliding at neutral gear, MK   

Malfunction Cause 

Solution 

Improper ignition timing 

Adjust ignition timing 

Throttle body or cable fails to return 

Clean throttle, adjust or replace throttle cable 

Intake system leaking 

Maintain or replace relevant component 

Improper valve clearance 

Adjust valve clearance 

Improper fuel pressure 

Normal pressure: between 250kPa and 300kPa. When fuel 
pump, fuel filter and fuel pressure controller operating 
abnormally, shall replace relevant component. 

Electric injection unit operates poorly 

Stepping motor stuck, clean it. Throttle position sensor 
sensitive poorly, adjust or replace it. Fuel injector leaking, 
replace it. Intake temperature pressure sensor malfunction, 
replace it. (see the table above for details of check method) 

High idle 
speed when 
sliding at 
neutral gear, 
MK 

ECU software malfunction or inner damage

Software malfunction, update it or check ECU, whether it is 
damaged. Replace ECU when necessary. 

 

 

High idle speed when sliding at neutral gear, 

MK

Throttle body or cable fails to return 

Improper ignition timing 

Intake system leaking 

Improper valve clearance 

Electric injection unit operates poorly 

ECU software failure or inner damage 

Check 

Check and replace 

Check and adjust 

Replace 

Check and replace 

Adjust 

Operates poorly 

Leak 

Abnormal 

Fails to return 

Abnormal 

Abnormal 

Normal 

Normal 

Normal 

Normal 

Normal