Chery Fora (Elara A520). Manual - part 146

CHERY·A21 SERVICE MANUAL ENGINE EFI SYSTEM

make the heat exchange different of the heat
diaphragm of both sides.

  This  will  make  the  temperature  of  two  sensing
element  measuring  point  inside  of  the  flowmeter
Changes  differently  and  appears  difference  in
temperature.  And  the  difference  of  the  temperature
will  increase  with  the  increase  of  the  airflow.
Big/small  and  positive/negative  of  the  temperature
difference  improved  the  quality  and  direction  of  the
airflow.  And  the  inside  evaluate  circuit  will  transfer
the  temperature  difference  to  voltage  signal  and
output.

5)Working temperature:-40--125℃

6)Malfunction and diagnosis method

l Reason: sensing element is polluted by the dust

particle, oil and water and causes the part invalid.

l Service notice: 1, it is prohibited to use erosion

liquid to clean sensing element during service; 2,
not  to  use  high  pressure  air  to  impact  sensing
element;  3,  make  sure  there  are  no  dust  into  air
pipe  when  you  change  air  cleaner  and  no
unqualified air into air cleaner.

l Simple measuring method: static measurement:

(zero flow measurement) No. 3 grounding; No. 4
input 5V reference voltage; No.2 input 14V rated
voltage; check No. 5 output voltage, if the output
is  bigger  than  1.025V,  we  can  confirm  the
function  of this  sensor  is  not  qualified. Dynamic
measurement:  if  it  is  confirmed  the  sensor  is
broken,  connect  a  tail  gas  analysis  meter  to
exhaust pipe and check  it by using “two working
conditions  method”:  1,  idle  speed  working
conditions; 2, 2000rpm stable working conditions.
Check the reading of HC  、CO、CO

, normally

HC<100ppm CO<0.5%,CO

>13.5%

3.10 DOUBLE SPARK IGNITION COIL

1)Exterior and pin definition

No. 1 coil primary winding connect with No.5 pin of
ECU; No. 2 coil primary winding connect with No. 2
pin of ECU; No. 3 and No.4 pins connect with power

CHERY·A21 SERVICE MANUAL ENGINE EFI SYSTEM

anode.

2)Installation position: on the engine

3)Purpose:  Ignition  coil  transfers  the  low  voltage  of
primary  winding  to  high  voltage  of  secondary
winding, and produce spark by spark plug discharging
then  burning  the  combustible  gas  inside  of  the
cylinder.

4)Working principle

Ignition  coil  ZS  -  K22  is  made  up  of  two  primary
windings,  two  secondary  windings,  mandrel,  and
casing. When one of the primary windings grounding
chunnel  is  connected,  the  primary  winding  is  in
charging.  Once  the  circuit  is  cut  off  by  ECU,  the
charging is stopped. At the same time the high voltage
is  sensed  in  the  secondary  winding  and  making  the
spark  plug  discharging.  There  is  a  different  with  the
distributor ignition coil: for the ignition coil ZS - K22,
there  is one  spark  plug  on  both  side  of  the secondary
winding,  and  the  both  spark  plugs  can  ignite  at  the
same  time.  These  two  primaries  connect  and
disconnect

power

alternatively.

And

correspondently these two secondary windings
discharge alternatively.

5)Working voltage:14V

Working temperature:-40—120℃

6)Malfunction and diagnosis method

l Malfunction: can not start.

l Reason: current is too big and got burnt, damaged

by outside force etc..

l Service notice: forbid to use "short circuit test

igniting method” to test ignition function,
prevents the electronic controller from damaging.

l Simple measuring method: (disassemble the joint)

leave digital multimeter at ohm shift, connect two
meter  pen  to  two  pins  of  primary  winding,  the
resistance  value  is  0.42-  0.58Ωwhen  it  is  20℃;
secondary  winding  resistance  value  is  11.2-
14.8kΩ.

Chart 3-18 Exterior Drawing of Ignition

Coil

Connect To Main

Relay Pin No.87

Chart 3-19 circuit Diagram of Ignition

Coil

CHERY·A21 SERVICE MANUAL ENGINE EFI SYSTEM

3.11 CARBON CANISTER SOLENOID VALVE

1)Exterior drawing and pin definition

Canister control valve only has two pins; one is
connect to No.87 pin of main relay output end; and
another pin connected to No. 5 pin of ECU.

2)Installation position: Canister vacuum pipe of
intake manifold

3)Purpose:  Control  the  quantity  of  the  cleaning
flow  from  canister  to  air  intake  chief  pipe.  The
absorption  of  the  canister  is  limited  so  if  the
gasoline  vapor  adhesive  to  canister  can  not  be
consumed  the  gasoline  vapor  will  volatility  to
outside and pollute the air.

4)Working principle

Canister  is  made  up  of  electromagnetic  coil,
armature  and  valve  etc..  There  is  strainer  on  the
intake.  The  flow  quantity  passes  canister  valve  is
correlate not only to electrical impulse duty ratio of
canister  control  valve  output  by  ECU,  but  also  to
the  pressure  difference  between  canister  valve
intake  and  outlet.  When  there  is  no  electronic
impulse, the canister control valve will shut down.

5)Working voltage:9—16V

Working temperature:-30--120℃

6)Malfunction and diagnosis method

l Malfunction: Function invalidation.

l Reason: some particle coming to inside of valve

causes erosion or poor sealing.

l Service notice: 1, let the airflow direction be

accord  with  the  regulation;  2,  when  there  are
black  particle  inside  of  valve  and  causes  the
control  valve  invalidation, the valve  need to be
changed,  please  check  the  canister  working
conditions;  3,  avoid  the  water,  fuel  and  other
liquid into valve during the service; 4, hang the
valve  on  the  tube  to  avoid  the  transferring  of
solid sound.

l Simple measurement method: (disassemble the

Chart 3-20 Exterior Drawing of Canister

Solenoid

Connect To Main Relay

Canister Solenoid Valve

Chart 3-21 Circuit Diagram of Canister

Solenoid

CHERY·A21 SERVICE MANUAL ENGINE EFI SYSTEM

joint) leave digital multimeter to ohm shift, two
meter pen connect to the pins of canister valve,
it is 26±4 Ω when it is 20

℃

3.12 FUEL PRESSURE REGULATOR

1)Exterior drawing

2)Installation position: Fuel bracket assembly

3)Purpose: Adjust the pressure inside of fuel pipe,
keep the System pressure around 350Kpa.

4)Working  principle:  See  chart  3-  23,  one  piece  of
flexible film made up of rubber and fiber separate the
fuel  pressure  regulator  into  two  compartments.  The
upper  compartment  communicates  to  the  air,  and
there  is  spring  inside.  The  lower  compartment  is  full
of  fuel  entering  from  the  fuel  intake  under  the  fuel
pressure regulator. The lower part of the film gets the
pressure from fuel and the upper part gets the pressure
from  air  and  spring.  The  film  can  distort  and  drive
valve  seat  making  the  valve  open  and  close,  but  the
distortion is smaller the acting force of the spring may
be seemed as not changed. So the opening and closing
of  the  valve  is  decided  by  the  pressure  difference  of
the fuel pressure from  lower compartment and the air
pressure  from  the  upper  compartment.  If the  valve  is
closed  at  first,  then  the  fuel  pressure  increased
causing  the  pressure  difference  between  upper  and
lower  compartments  increased.  At  last  the  film  was
raised  up  by  the  fuel  pressure  and  valve  is  opened.
The  fuel  return  to  fuel  tank  from  oil  return  port  of
pressure  regulator,  the  fuel  pressure  decreased  until
the valve  is closed. If the engine changes its working
conditions now, the pressure difference of fuel system
and the air pressure is about the same.

5)Malfunction and diagnosis method

l Malfunction: fuel pressure is too high or too low,

difficult to start.

l Reason: long time using without maintenance

causing: 1, strainer jammed; 2, particle causes big
leaking; 3, man made mechanical damages.

l Service notice: 1, prohibit to use high pressure air

blowing film element; 2, Forbid using strong

Chart 3-22 Fuel Pressure Regulator

Chart 3-23cutaway View of Fuel

Pressure Regulator

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