1987 MAZDA 626 fuel

4A INTAKE AIR TEMPERATURE CONTROL SYSTEM
System Inspection
Bimetal type
[FE 8Valve—Unleaded Fuel]
Move the control valve inside the air cleaner, and
check that it moves freely and that spring force is felt.
System Inspection
Manual type
[Middle East and F6—General]
Change the summer-winter change lever and check
that it moves smoothly.
76G04A-119
4A—62

PURGE CONTROL SYSTEM 4 A
PURGE CONTROL SYSTEM
[FE 8VALVE—UNLEADED FUEL]
Vaccum switch valve -4
I
Water thermo valve
76G04A-120
This system supplies additional air to the intake manifold to improve the driveability when the engine
coolant temperature is above 50°C (122°F).
TROUBLESHOOTING
Possible cause Vacuum switch valve Water thermo valve
Page 4A—63 4A—66
Checking order 1 2
VACUUM SWITCH VALVE
1. Connect a vacuum pump to the purge control
valve as shown in the figure.
2. Blow through the valve from port A and check that
air does not come out of port B.
3. Apply 100 mm-Hg (3.94 InHg) vacuum.
4. Blow through port A and check that air comes out
of port B.
5. Replace if necessary.
76G04A-121
4A-63

4A EGR SYSTEM
EXHAUST GAS RECIRCULATION
(EGR)
SYSTEM
FE 8VALVE—UNLEADED FUEL
This system introduces exhaust gas into the intake manifold to reduce NOx emissions.
4A—64

IDLE-UP CONTROL SYSTEM 4 A
FE (Middle East) and F6 (General)
Possible cause
jrvo

diaphragm

3
jrvo

diaphragm

n c o> (0
E 3 3 O
® >
a >
•o o c e
£ O **
S M O
£ O
'i (0 (0
O <
o a
o E W 0)
lm Q.
c a k 4) -
9-5
"S "5 (O > CO < a. DC H Js * OC M
Page 4A—72 4A—74 4A—74 Section 15 4A—75 Section 16
Checking order 1 2 3 4 5 6 7 8
76G04A-136
FE 8Valve—Unleaded Fuel
Posible cause

Engine

control

unit

terminal

Servo

diaphragm

Vacuum

signal

Solenoid

valve £ O **
S CO O
£ U
S <0 U) Relay
(for
A/C) ** n ** w o E «
Refrigerant
pressure

switch
H D I Servo

diaphragm

Vacuum

signal

Solenoid

valve
< a. Relay
(for
A/C)
H Refrigerant
pressure

switch

Page 4A—91 4A—72 4A—74 4A—74 Section 15 4A—75 Section 16
Checking order 9 1 2 3 4 5 6 7 8
76G04A-137
4A—71

4A IDLE-UP CONTROL SYSTEM
76G04A-144
76G04A-145
76G04A-146
Vacuum Signal [Equipped with A/C, only FE and
F8 (Except Middle East and General)]
1. Start the engine and run it at idle.
2. Disconnect the vacuum hose from the servo di-
aphragm.
3. Place a finger over the hose.
4. Increase the engine speed, and check for vacuum.
Engine model Engine speed Vacuum
pj| (Except Middle) Below 2,300 rpm Yes pj| (Except Middle) Above 2,300 rpm No
FE (Unleaded fuel) Below 1,500 rpm Yes FE (Unleaded fuel) Above 1,500 rpm No
F6 (Singapore) Below 2,100 rpm Yes F6 (Singapore) Above 2,100 rpm No
General and Middle East
1. Start the engine and run it at idle.
2. Disconnect the vacuum hose from the servo di-
aphragm.
3. Place a finger over the hose.
4. Operate the A/C or P/S.
5. Check that vacuum is felt.
P/S Switch
1. Start the engine and run it at idle.
2. Disconnect the power steering switch connector.
3. Connect an ohmmeter to the power steering
switch.
4. Turn the steering wheel all the way to either the
right or left, and check for continuity.
P/S Continuity
Operated Yes
Not operated No
5. Replace if necessary.
Solenoid Valve (A/C)
1. Disconnect vacuum hose A from the servo di-
aphragm.
2. Disconnect vacuum hose B from the solenoid
valve.
3. Disconnect the solenoid valve connector.
4. Blow air through the valve from hose A and check
that it comes out of port C.
76G04A-147
4A-74

4 A EVAPOTATIVE EMISSION CONTROL SYSTEM
EVAPORATIVE EMISSION CONTROL SYSTEM
(MIDDLE EAST)
76G04A-155
Operation
Cold engine — below 50°C (122°F)
The No. 1 purge control valve does not operate because the vacuum passage of the water thermo
valve is opened to the atmospheric air side.
Warm engine — above 50 °C (122°F)
1. During normal driving, the carburetor vacuum signal is led to the No. 1 purge control valve with
the result that fuel vapors are drawn into the intake manifold.
4A—78

4A CONTROL SYSTEM
RELATIONSHIP CHART
O: Related
X
: Not
related
IGNITION COIL
X X
O O O
X
O
X

WATER
THERMO
SWITCH
RADIATOR O O
X X X X
o O WATER
THERMO
SWITCH INTAKE
MANIFOLD o
X X X X
O o
X

VACUUM SWITCH
X X X X X X X
O
IDLE SWITCH
X X
O O O
X X X

A/C SWITCH
X X X X X
O
X X

P/S SWITCH
X X X X X X X X

E/L SWITCHES
/ Headlight Switch


( Rear defroster switch
J

\ Fan speed control switch
/
X X X X X
O
X X

INHIBITOR SWITCH
X X X X X
O O
X

ENGINE CONTROL UNIT
X
o O O O O o O

\
INPUT

DEVICE

AND
ENGINE

CONTROL

UNIT

OUTPUT
DEVICE
PTC
HEATER

CHOKE

OPENER
(FE
and
F8
—
ECE,
Hong
Kong,
&

Singapore)

COASTING
LEANER
COAST

ENRICHMENT

SOLENOID

VALVE
AIR

BYPASS
SOLENOID
VALVE
IDLE-UP
SOLENOID
VALVE
IGNITION
TIMING
CONTROL
SYSTEM
MAIN
AIR
BLEED
CONTROL
SYSTEM

*
FE
8Valve—Unleaded Fuel:
O
(Related)
General and
FE
12Valve—ECE, Hong Kong, Singapore:
X
(Not related)

76G04A-167
4A—84

CONTROL SYSTEM 4 A
Terminal (Wire color) Connected to Condition Voltage

0 (BY)
Ignition switch*
(START position) Ignition switch
ON
Below 1.5V 0 (BY)
Ignition switch*
(START position) Cranking Battery voltage
P
(LW) Solenoid valve (A/C) A/C switch
ON
and engine speed below approx.
2,300
rpm
Below 1,5V
Others Battery voltage
Q (YW) Idle-up solenoid valve Headlight switch ON, rear defroster switch ON,
fan
speed control switch
is
3rd
or
4th position, A/C oper-ated,
or
engine coolant temperature below 72°C (162°F)
Below 1,5V
Others Battery voltage
R
(LB)
Fan speed control switch Fan speed control switch
in
3rd
or
4th position Below 1,5V R
(LB) Fan speed control switch OFF Battery voltage
*
Not
used
76G04A-173

{
Q
0
><
K
X
G E C A
^

R P
R X
J H F D B

FE 8Valve — Unleaded Fuel
Terminal (Wire color) Connected to Condition Voltage

A
(L)
Coast enrichment solenoid valve Engine speed approx. 1,500—2,300 rpm and idle switch
ON

Below 1,5V A
(L)
Coast enrichment solenoid valve
Others Battery voltage
B
(B)
Ground
—
Below 1,5V
C (LB)
Air bypass solenoid valve Engine speed above approx. 3,500 rpm and idle
switch
ON

Below 1,5V C (LB)
Air bypass solenoid valve
Others Battery voltage
D
(YL)
Ignition coil Ignition switch
ON or
engine running Battery voltage
E
— — —

F
(BW)
Ignition switch Ignition switch
ON
Battery voltage
G (YW) Slow fuel cut solenoid valve Engine speed above approx. 2,300 rpm and idle
switch
ON

Battery voltage G (YW) Slow fuel cut solenoid valve
Others Below 1.5V
H
(LW) A/C switch A/C operated and engine speed above approx.
1,500 rpm
Battery voltage H
(LW) A/C switch
A/C not operated
or
engine speed below approx.
1,500 rpm
Below 1,5V

4A—91