37 

 

Engine idle speed decreases when activating 

head beam or fan 

Generator belt loose 

Earth lead loose 

Generator operates abnormal 

Battery open circuit 

Idle speed controlling valve or stepping motor 

failure 

Combined switch short circuit 

The power of head beam or the load of fan is over normal value

Poor ECU signal 

Engine operates abnormal 

Check 

Clean and replace 

Check 

Check or replace 

Check and replace 

Replace 

Replace 

Adjust 

Check 

Open circuit 

Loose 

Poor 

Low 

Short circuit 

Over load 

Abnormal 

Abnormal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

 
 

 

 

38 

 

No. 022 Exhaust pipe blows water   

Malfunction Cause 

Solution 

Water log in silencer 

Check silencer inner water log. The tail water exhaust port of 
silencer is blocked, and blows large quantity of water when 
accelerating. Punch a hole on silencer to drain water. 

Throttle body water leak 

Maintain or replace throttle body. 

Gasket damaged 

Maintain cylinder and cylinder head surface, replace gasket. 

Crack or blow hole in cylinder head

Check cylinder head, whether there is crack or blow hole in it, 
which results coolant flow into cylinder. Remove cylinder head 
and inspect the crack in it, by magnaflux.  Replace cylinder 
head when necessary. 

Engine vibration when 
idling, with abnormal 
noise, and cooling 
water is always 
polluted. 

Crack or blow hole on clinder wall

Check cylinder wall, whether there is crack or blow hole in it, 
which results coolant flow into cylinder. Remove cylinder wall 
and inspect the crack in it, by magnaflux. Replace cylinder 
head when necessary. 

 

 

Exhaust pipe blows water 

Water log in silencer 

Throttle body water leak 

Gasket damage 

Crack or blow hole in cylinder head 

Crack or blow hole on clinder wall 

Check 

Replace 

Replace 

Replace 

Replace 

Damage 

Water log 

Water leak 

Crack or blow hole 

Crack or blow hole 

Normal 

Normal 

Normal 

Normal 

 
 

 

 

39 

 

No. 023 Engine shuts off when accelerating   

Malfunction Cause 

Solution 

Fuel tank lacks of fuel 

Fill fuel 

Poor fuel quality 

Replace with standard fuel 

Air filter blocked 

Clean or replace air filter 

Low intake vacuum 

Vacuum sense port of intake pressure sensor is blocked by carbon 
deposit. Clean it. Intake vacuum pipe cracked, and results vacuum 
decreased, mixture gas rarefied, as well as engine shut-off when 
vehicle picking up. 

Exhaust system partly blocked 

Check 3-way catalytic converter, whether it is dropped or blocked.

Ignition maladjustment 

Check fly wheel signal rim, whether it operates correctly. Check 
tachospeed sensor, whether it is normal. Check valve timing, 
whether it is normal. Check ignition system, whether it contains 
ignition miss. 

Positive electrode of oxygen sensor 

short or open circuit. 

Check output voltage of oxygen sensor, in idle condition the value 
shall be about 4.5V. Otherwise, replace oxygen sensor. 

Fuel pressure decrease when 

accelerating 

Normal fuel pressure is between 250kPa and 300kPa. Check fuel 
pump, fuel filter and fuel pressure controller etc. Replace them 
when necessary. 

Throttle position sensor short or 

open circuit 

Check throttle position sensor, whether there is short or open 
circuit. Replace it when necessary. 

Engine shut-off 
when vehicle 
picking up 

Low cylinder pressure 

Check operation of each cylinder, whether it operates normal. 
Disassemble and maintain engine when necessary. 

 
 

 

 

40 

 

Engine shuts off when accelerating 

Fuel tank lacks of fuel

Poor fuel quality   

Air filter blocked 

Low intake vaccum 

Exhaust system blocked 

Ignition maladjustment 

Fuel pressure decrease when accelerating 

Positive electrode of oxygen sensor short or 

open circuit 

Low cylinder pressure 

Replace 

Replace 

Check 

Check 

Check 

Replace 

Fill 

Clean or replace 

Check and replace 

Blocked 

Lack 

Poor quality 

Low 

Blocked 

Abnormal 

Abnormal 

Abnormal 

Decrease 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal 

Normal