CHERY·A21 SERVICE MANUAL ENGINE EFI SYSTEM
63
7. Regular starts but the idle speed is not steady during engine heating.
General failure component: 1), water in fuel; 2), coolant temperature sensor; 3), spark
plug; 4), throttle valve and idle speed by pass port; 5), air intake port; 6), idle speed
regulator; 7), engine mechanical.
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 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
