1987 MAZDA 626 temperature

TROUBLESHOOTING GUIDE
3B

SPECIFICATIONS

Cooling system Water-cooled, forced circulation
Coolant capacity liters (US
qt,
Imp
qt)

With heater 9.5 (10.0, 8.4) Coolant capacity liters (US
qt,
Imp
qt)

Without heater 9.0 (9.5, 7.9)
Water pump Type Centrifugal, timing belt driven Water pump
Water seal Unified mechanical seal
Thermostat
Type Wax, two stage
Thermostat
Opening temperature °C(°F) Main Sub
Thermostat
Opening temperature °C(°F)
86.5-89.5 (188-193) 78.5—81.5 (173-179) Thermostat
Full-open temperature °C(°F) 100 (212) 100 (212)
Thermostat
Full-open lift
mm (in)
8.0 (0.31) min. 1.5 (0.06) min.
Radiator
Type Corrugated
fin

Radiator Cap valve opening pressure
kPa (kg/cm2,
psi)
74-103 (0.75-1.05, 11—15)
Cooling
fan

Type Electric
Cooling
fan

Capacity
W
120
Cooling
fan
Switching temprature orvopi OFF
- ON ^
91 (196) Cooling
fan

Number
of
blade 4
Cooling
fan

Outer diameter
mm
(in) 340 (13.4)

76G03B-003
TROUBLESHOOTING GUIDE
Problem Possible Cause Remedy Page
Overheating
Insufficient coolant Add 3B-
4

Coolant leakage Repair
—

Radiator fins clogged Clean 3B—
6

Radiator cap malfunction Replace 3B—
5

Cooling fan malfunction Repair 3B-11 Thermostat malfunction Replace 3B—
9

Water passage clogged Clean 3B—
4

Water pump malfunction ReDair
or
replace 3B—
7

Corrosion
Impurities
in
coolant Replace 3B-
4

76G03B-004
3B—3

THERMOSTAT 3B
THERMOSTAT
REMOVAL
1. Drain the engine coolant.
2. Disconnect the upper radiator hose, and water
thermo switch connector.
3. Remove the thermostat cover.
4. Remove the thermostat.
76G03B-010
76G03B-011
Sub valve Main valve
I
INSPECTION
Check the thermostat. Replace if necessary.
1. Visually check that the valve is airtight.
2. Place the thermostat and a thermometer in water.
3. Gradually heat the water and check the following:
Valve opening temperature
Sub valve : 78.5—81.5°C (173—179°F)
Main valve : 86.5—89.5°C (188—193°F)
Full open lift
Sub valve : 1.5 mm (0.06 in) min. at
100°C (212°F)
Main valve : 8 mm (0.31 in) min. at
100°C (212°F)
Valve closing temperature
Sub valve : 75°C (167°F)
Main valve : 83°C
(181
°F)
69G03B-012
76G03B-012
INSTALLATION
1. Install the thermostat into the thermostat case with
jiggle pin at the top.
2. Install a new gasket with the seal print side facing
the thermostat case.
3. Install the thermostat cover.
Tightening torque:
7—10 N-m (70—100 cm-kg, 61—87 in-lb)
4. Install the upper radiator hose and water thermo
switch connector.
5. Replenish the coolant.
6. Start the engine and check for leaks.
3B-9

3B COOLING FAN
WATER THERMO SWITCH
1. Remove the cooling fan water thermo switch.
Note
Make sure that the ignition switch is OFF. If
not, the fan will operate when the connector
is removed.
76G03B-017
76G03B-018
2. Place the water thermo switch in water.
3. Heat the water gradually, and check for continui-
ty of the switch with an ohmmeter. Replace if
necessary.
Temperature Continuity
Above
91
°C (208°F) No
Below 84°C (183°F) Yes
4. Install the water thermo switch and a new O-ring.
Tightening torque:
6—9 N-m (60—90 cm-kg, 52—78 in-lb)
Caution
Do not use sealing tape.
3B-12

4A
FUEL AND EMISSION
CONTROL SYSTEMS
(CARBURETOR)
OUTLINE 4A— 2
SYSTEM DIAGRAM 4A— 2
VACUUM HOSE ROUTING
DIAGRAM 4A— 5
EMISSION COMPONENTS
LOCATION 4A— 8
COMPONENT DESCRIPTIONS 4A—12
SPECIFICATIONS 4A—15
TROUBLESHOOTING GUIDE 4A—17
PARTS INSPECTION 4A—23
AIR CLEANER ELEMENT 4A—23
ACCELERATOR LINKAGE 4A—23
INTAKE MANIFOLD 4A—23
CHOKE CABLE 4A—23
FUEL SYSTEM 4A—24
TROUBLESHOOTING 4A—25
CARBURETOR 4A—26
FUEL PUMP 4A—35
FUEL TANK 4A—36
SEPARATOR 4A—37
TWO-WAY CHECK VALVE 4A—37
THREE-WAY CHECK VALVE 4A—37
FUEL FILTER 4A—37
IDLE SPEED AND IDLE MIXTURE.. 4A—38
ADJUSTMENT 4A—38
AUTO-RETURN CHOKE SYSTEM... 4A—40
TROUBLESHOOTING 4A—40
PTC HEATER SYSTEM 4A—42
TROUBLESHOOTING 4A—42
DECELERATION CONTROL SYSTEM 4A—45
TROUBLESHOOTING 4A—45
BYPASS AIR CONTROL SYSTEM.. 4A—48
DASH POT 4A—50
ANTI-AFTERBURN VALVE 4A—50
MAIN AIR BLEED CONTROL
SYSTEM 4A—51
SLOW FUEL CUT SYSTEM 4A—53
COAST ENRICHMENT SYSTEM .... 4A—54
COASTING LEANER SYSTEM 4A—56
AIR INJECTION SYSTEM 4A—58
INTAKE AIR TEMPERATURE CONTROL
SYSTEM 4A—60
TROUBLESHOOTING 4A—60
PURGE CONTROL SYSTEM 4A—63
VACUUM SWITCH VALVE 4A—63
EXHAUST GAS RECIRCULATION
(EGR) SYSTEM 4A—64
TROUBLESHOOTING 4A—65
POSITIVE CRANKCASE VENTILATION
SYSTEM 4A—67
PCV VALVE 4A—67
IDLE-UP CONTROL SYSTEM 4A—68
TROUBLESHOOTING 4A—70
IDLE-UP SOLENOID VALVE 4A—76
EVAPORATIVE EMISSION CONTROL
SYSTEM 4A—78
TROUBLESHOOTING 4A—79
IGNITION TIMING CONTROL
SYSTEM 4A-80
TROUBLESHOOTING 4A—81
CONTROL SYSTEM 4A-83
RELATIONSHIP CHART 4A—84
ENGINE CONTROL UNIT 4A—86
INHIBITOR SWITCH 4A—93
IDLE SWITCH 4A—93
VACUUM SWITCH 4A—94
WATER THERMO SWITCH 4A—95
EXHAUST SYSTEM 4A—96
76G04A-001

Diaphragm

Intake air temperature
Water thermo switches*2 Vacuum switch*2 E/L switches*2 Inhibitor switch*2 Ignition coil
Fuel pump
Water thermo
switch*2
(on radiator)
*1 MTX
*2 Except F6
*3 F6
*4 Except F8 ATX and F6
*5 F6 MTX
*6 Except F8 ATX and F6 ATX
*7 F8 MTX and FE

FE MIDDLE EAST DiaPhra3m*2 Intate air temperature
F6 GENERAL
Choke opener*
•Vacuum switch
E/L switch
Inhibitor switch*4
Water thermo
switches
Separator Charcoal canister
Water thermo valve *1 Middle East
*2 FE and F8 General
*3 Middle East MTX
*4 ATX

OUTLINE
4A

Previous

626
Unlead-
ed

fuel
O O O O O O X O O O X

Previous

626

Leaded
fuel
O X X O O X X X O X

New
626
FE
8
Valve
Unlead-
ed

fuel
o O O O O O X X O O O

New
626
Sin-
gapore

o O X O O m O
O

(FE

&
F8)
O
O

(FE

&
F8)
O O

New
626

Middle
East
o X X O O X X X X X O

New
626

General

X
O

(FE

& F8)
X O O X
O

(FE

&
F8)
O

(FE

&
F8)
O

(FE

&
F8)
X o

New
626
ECE
&

Hong
Kong
o O X O O * O O O O O o

Remark
• Adjustment
speed:

2,200

±
100
rpm
(in
neutral).
• MTX • Operation:
Coolant
tempera-

ture

more
than

50°C

(122°F).

Mechanical
type
Installed
on
carburetor.
Improvement
of
product
quality.

Function

Allows

throttle
to
gradually
close

during

deceleration.

Reduces

CO

and
HC
emission.

Detects

electrical
signal
from
in-
put
devices
and
controls
output
devices. Supplies
exhaust
gas
to
intake
manifold
to
reduce
NOx

Filters

fuel

Provides

fuel
to
carburetor.
Detects
when
throttle
valve
fully
closed. Opens
fuel

passage

to
secon-
dary
stage
of
carburetor.
Controls
shutter
valve
by
intake

air
temperature. Prevents
carburetor

icing.

Supplies
fresh
air
to
exhaust
manifold
to
reduce
CO
and
HC
emissions. Prevents
fuel
from
flowing
into

two-way

or
three-way
check

valve

Component

Dashpot Engine
Contorol
Unit

EGR

Control
Valve

Fuel

Filter

Fuel

Pump
Idle
Switch

Idle-up

Solenoid

Valve
Intake
Air
Temperature
Control
Valve

PTC

Heater

Reed

Valve

Separator

•a a> a -a .2-S
3
9-a a) 5 u- O UJ
z

Ox

111 IL •a c x" Ul
V (-
U.ps •o u.
-
X
_ X
I-
o-t-
s ®
s
*
o *
oo
x to
U. UJ
u.
T- oi CO
4 A—13

TROUBLESHOOTING GUIDE
4A

TROUBLESHOOTING GUIDE
F6 (GENERAL)
The Troubleshooting Guide lists the systems most likely to cause
a
given symptom. After finding the
system(s)
to
check, refer
to
the pages shown
for
detailed guides
for
each system.
\\ POSSIBLE CAUSE
\ PAGE


SYMPTOM
Air

cleaner
(Air
cleaner
element)
intake
air
temperature
control

system
Idle

adjustment
Fuel
system
(Carburetor,
Fuel
pump)

idle-up

control
system
Exhaust
system
Positive
crankcase
ventilation

system
Auto-return
choke
system

\\ POSSIBLE CAUSE
\ PAGE


SYMPTOM 4A—23 4A—60 4A—38 4A—24 4A—68 4A—96 4A—67 4A—40
1 Hard start
or
won't start (Cranks
OK)
1 2

2 Engine stalls During warm
up
3 2 1 4
2 Engine stalls After warm
up
4 2 5 1 3

3 Rough Idle During warm
up
3 2 1 4
3 Rough Idle After warm
up
3 2 5 1 4

4 High idle speed after warm
up
1 3 2

5 Poor acceleration, hesitation, or lack
of
power
1 2 3

6 Runs rough
on
deceleration
1

7 Afterburn
in
exhaust system
1

8 Poor fuel consumption
2 1 4 3

9 Fails emission test
2 1 4 5 3

76G04A-015
The numbers of the list show the priorities
of
inspections from the most possible to that with the lowest
possibility.
These were determined
on
the following basis:
• Ease
of
inspection
•
Most possible system
•
Most Possible point
in
system
TROUBLESHOOTING PROCEDURE:
1st Check the following items:
Electrical system
1) Battery condition
2) Fuses
Ignition system
1) Spark plugs
2) Ignition timing
Fuel system
1) Fuel level
2) Fuel leakage
3) Fuel filter
4) Idle speed
Intake
air
system
1) Vacuum
or air
leakage
2) Vacuum hose routing
3) Accelerator cable
4) Choke cable
2nd Check Fuel and Emission Control Systems
Engine
1) Compression
2) Overheating
Others
1) Clutch slippage
2) Brake dragging
4 A-17