CHERY·A21 SERVICE MANUAL ENGINE EFI SYSTEM
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8. Regular starts but idle speed is not steady after the engine heating.
General failure component: 1), water in fuel; 2), coolant temperature sensor; 3), spark
plug; 4),throttle valve and idle by pass port; 5), air intake port; 6), idle speed regulator;
7), engine mechanical part.
General diagnosis flow:
No. Operating steps Result Follow up steps
Yes
Repair the air
intake system
1
Check the air cleaner if it is jammed; check the air intake
port if it is leaking.
No Next step
Yes Next step
2
Check spark plugs in every cylinder and observe its type
and clearance if it is accord with the regulation.
No
Adjust or
replace
Yes
Cleaning the
related parts3
Disassemble the idle speed regulator and check the throttle
valve and idle speed by pass port if there is carbon
deposition
No Next step
Yes
Repair the line
or replace
sensor
4
Pull off coolant temperature sensor joint and start the
engine; observe the engine if it is idle speed unsteady
during warming up the engine.
No Next step
Yes Replace part
5
Disassemble the injector, check the injector using the
injector special cleaning analysis meter and observe if it is
leaking or jammed or overflowing.
No Next step
Yes Change fuel
6
Check fuel conditions and check if the failure is appeared
just after the fuel refilling
No Next step
Yes Trouble shoot
7
Check pressure conditions of every cylinder and observe if
there is big pressure difference between the cylinders.
No Next step
Yes Diagnosis help
8
Connect EFI system adaptor, turn on the ignition switch;
check the power supply of pin No.12, 13, 44, 45 and No.63
if it is in right conditions; check pin armature of No.3, 51,
53, 61 and No.80 if it is in right conditions.
No
Repair the
corresponding
line
