CHERY·A21 SERVICE MANUAL ENGINE EFI SYSTEM
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13. The performance is poor when it is accelerated.
General failure component:1) water in fuel; 2) air intake pressure sensor and throttle
position sensor; 3) spark plug; 4) ignition coil; 5) throttle valve and idle speed by pass
port; 6) air intake port;7) idle speed regulator; 8) injector; 9) ignition timing; 10)
exhaust pipe.
General diagnosis flow:
No. Operating steps Result
Follow up
steps
Yes Repair
1
Check if there are failures like clutch skidding, low tyre
pressure, brake dragging, wrong tyre size, and wrong four
wheel positioning etc..
Next step
Yes
Repair the air
intake system2 Check the air cleaner if it is jammed.
No Next step
Yes Next step
3
Connect the fuel pressure meter ( connecting point is the
front end of fuel distributing pipe assembly fuel intake
pipe); start the engine and check fuel pressure at idle speed
if it is around 260kpa; take off the vacuum pipe from fuel
pressure regulator check the fuel pressure if it is around
300kpa.
No
Repair the
fuel supplying
system
Yes Next step
4
Pull off one of the cylinder separating line and connect
spark plug to it; keep the spark electrode around 5mm away
from engine body; start the engine and check the high
pressure fire strength if it is regular.
No
Repair
ignition
system
Yes Next step
5
Check spark plugs in every cylinder and observe its type and
clearance if it is accord with the regulation.
No
Adjust or
replace
Yes
Clean related
part6
Disassemble idle speed regulator and check throttle valve,
idle speed regulator and idle speed by pass port if there is
carbon deposition.
No Next step
Yes Next step
7
Inspect air intake pressure sensor, throttle position sensor
and its line if it is working correctly.
No
Repair line or
replace sensor
Yes
Replace fault
part8
Disassemble the injector, check the injector using the
injector special cleaning analysis meter and observe if it is
leaking or jammed.
No Next step
Yes Replace fuel
9
Check fuel conditions and check if the failure is appeared
after the fuel refilling
No Next step
Yes Next step
10
Check the engine ignition order and ignition timing if it is
accord with the regulation.
No
Repair
ignition
timing
