YG48Q-5A Maintenance ManualEngine management system
155
No
Check the pump.
Check whether the
‘RMP’ data on the diagnostic tool shows the
real engine RPM.
Yes
Next
No
Check the crank sensor.
Pull out the spark plug, check whether the spark over is normal.
Yes
Next
No
Check the ignition system
Check whether the cylinder pressure is normal.
Yes
Engine is good.
No
Check the engine
Sta
rt
Dif
fi
c
u
lt
Check wether the fuel pump pressure is about 250kPa at idle.
Yes
Next
No
Check the pump.
Pull out the spark plug, check whether the sparkover is normal.
Yes
Next
No
Check the ignition system
Remove the connector of the engine temperature sensor, and
check whether the enigne start well.
Yes
Check the engine
temperature sensor
No
Next
With a little bigger throttle, check wheterh the engine starts
well.
Yes
Clean the throttle body and
bypass channel.
No
Next
Pull out the injector, and crank the engine. Check whether the
injection is normal.
Yes
Next
No
Clean or change the
injector.
Pull out the sprk plug, check whether it is wet or not
Yes
dry the plug and
combustion chamber.
No
Next
Check whether the cylinder pressure is normal or not
Yes
Engine is good
No
Check the engine
Uns
ta
b
le
i
d
le
Check whether the air filter is blocked and whether the intake
pipe leaks.
Yes
Intake system maintenance
No
Next
Whether there is carbon deposit at the throttle body and bypass
channel.
Yes
Clean the TB
No
Next
Check whether the IACV works well
Yes
Next
No
Check the IACV
Check whethe the fuel pressure is about 250kPa.
Yes
Next
No
Check the pump
Check whether the injeoctor is blocked.
Yes
Clean or change the
injector
No
Next
Make sue using the right type sprkplug
Yes
Next
No
Change the spark plug
Check whether the cylinder pressure is normal
Yes
Next
No
Check the engine
Remove the engine temperature sensor, and check whether
the engine works well
Yes
Change the senor
No
Next
Remove the TPS, check whether the engine works well
Yes
Change the sensor
No
Help
H
i
g
h
i
d
l
e
Check whether the throttle cable is stuck
Yes
Adjust the cable
Summary of Contents for YG48Q-5A
Page 38: ...YG48Q 5AMaintenance ManualFuel system 41 4 Fuel system...
Page 92: ...YG48Q 5AMaintenance ManualFrame and exhaust system 105 10 Frame and exhaust system...
Page 123: ...YG48Q 5A Maintenance ManualIllumination signal system 136 Circuit schematic drawing...
Page 126: ...YG48Q 5A Maintenance ManualIllumination signal system 139...
Page 133: ...YG48Q 5A Maintenance ManualEngine management system 146 Major parts and components...
Page 134: ...YG48Q 5A Maintenance ManualEngine management system 147...
Page 144: ...YG48Q 5A Maintenance ManualElectrical System Diagram 157 19 Electrical System Diagram...
