Chery A21 2005, Service Manual, Page: 267 / 475

Idle speed is not wel l 、 accel erate not well 、 can not st art
(start difficult)and etc.
Because of th e lackness of maintainen ce, there is coll oid
accumulate in the fuel injector and result in the i nvalidati on.
（ Remove the plug ） set the multimeter at the ohm p osition, the
two pens connect to the two pin s of fuel injector, the rating resistance is 12 Ω when it is
20 ℃ .
clean the fuel injector with specialized clean analyzer.
Fault d escription
Troubleshoot
：
Fault analysis ：
:
Advice ：
P ins: each f uel injector has two p ins . The o ne which is marked w ith "+" at one side o f the shell
c onnects to the 87th pin of main relay output port; the o ther conne cts to the 2 7th 6th
7th 47th
p in of ECU.
、 、 、
ECU sends electric impulse to the coil of injec tor and forms the magnetic field
power.Wh en the power incre ases enough to overcome the combined force o f release spring
pressure
、 needle v alve grav ity and friction, the needle va lve begin to rise and the fuel inject
procedure start. Wh en the fu el injection impulse stops, the pressure of relea se spring closes
the needle valve again.
can not start.
The current is too h igh to burn 、 damage by ou tside force.
It is forbidden to try the "short circuit test way" to test the ignition function, so as
to avoid the damage to electric controller.
（ Remove the plug ） set the multimeter at th e OHM position, connecti ng two
pens to the two p ins of primary win ding resp ectively. When it is 20 ℃ , the resistance is
0.42-0.58 Ω， and the secondary winding i s 11.2-14 .8k
Ω . Refer to table 20 ℃
Fault description
Troubleshoot
：
Fault analysis
：
Maintain notice ：
:
Br
2 2 2 2
G L O
47 7 6 27
ECU
Connects to 87#
of main relay
（ 1 ） Ignition coil
The ign ition coil transforms the low pressu re DC of battery to the high pressure
electricity, which gets through the spark plug and brings out spark to burn the mixture
in th e cylinder.
F igure9-16 Ignition coil
（ 2 ） Fuel injector
Figure9 -17 Fue l injecto r and its circuit
F uel injector
Th e1st coil prim ary windin g is connect ted
to the 5th pin of ECU
The 4th pin is em pty.
The 3rd pi n is connectted to the anode of
pow er
The 2nd coil primary winding is
connectted to the 2nd pin of ECU.
Ig nition coil
V
Ω
k Ω
mH
H
kV
kV
0.58
14.8
4.8
37.5
14
0.5
13.0
4.1
32.0
0.4 2
11. 2
3.4
26. 5
30
23
Elementary winding
Load 50pF
Load50p F//1M Ω
（ 20-25 ℃）
（ 20-25 ℃）
Min Ma x
Unit
Primary winding
Seco ndary winding
Resistance
Volta ge
Electromagnetic induction
Model
Cost
C apacity
Elementary winding
Seco ndary winding
Table 2
◆
Actuator
19