engine overheat MAZDA 626 1987 Workshop Manual

3A TROUBLESHOOTING GUIDE i
SPECIFICATIONS
^Engine model
Item ^__
FE-DOHC
FE 8-valve,
F8, F6...except
Middle East
.General
FE 12-valve
FE 8-valve F8, F6...only Middle East General

Cooling system Water cooled, forced circulation
Coolant capacity liters (US qt, Imp qt)
With heater 7.5 (7.9, 6.6) Coolant capacity liters (US qt, Imp qt) Without heater 7.0 (7.4, 6.2)
Water pump Type Centrifugal, timing belt driven Water pump
Water seal Unified seal
Thermostat
Type Wax, 2-stage Wax
Thermostat
Opening temperature °C(°F) Sub
.
83.5-86.5 (182-188) Main: 86.5-89.5 (188-193) 86.5-89.5 (188-193) 80.5-83.5 (177-182) Thermostat
Full-open temperature °C(°F) 100 (212) 95 (203)
Thermostat
Full-open lift
mm
(in) Sub: 1.5 (0.06) min.
Main: 8.0 (0.31) min. 8.5 (0.33) min.
Radiator
Type Corrugated
Radiator Cap valve opening pressure
kPa (kg/cm2, psi) 74-103 (0.75-1.05, 11-15)
Cooling
fan

Capacity
W

MTX 80
Cooling
fan

Capacity
W
ATX 120
Cooling
fan
Number
of
blade 4 Cooling
fan

Outer diameter
of
blade
mm
(in) MTX 320 (12.6)
Cooling
fan

Outer diameter
of
blade
mm
(in)
ATX 340 (13.4)

76G03A-003
TROUBLESHOOTING GUIDE
Problem Possible Cause Remedy Page
Overheating
Insufficient coolant Add 3A—
5

Coolant leakage Repair
—

Radiator fins clogged Clean 3A—
7

Radiator cap malfunction Replace 3A-
6

Cooling fan malfunction Repair 3A-12 Thermostat malfunction Replace 3 A-11
Water passage clogged Clean 3A—
5

Water
DumD
malfunction ReDair
or
replace 3A-
8
Corrosion
Impurities
in
coolant Replace 3A-
5
76G03A-004
3A—4

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

4A TROUBLESHOOTING GUIDE
F6 (SINGAPORE)
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)

Air

injection
system
Deceleration
control
system
Positive
crankcase
ventilation
system

Exhaust

system

Idle-up

control
system

POSSIBLE CAUSE
\ PAGE


SYMPTOM 4A-23 4A-60 4 A—38 4A—24 4A-58 4A-45 4A-67 4A-SW 4A—68
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
3 2 4 1

3 Rough idle During warm
up
3 2 1 4
3 Rough idle After warm
up
3 2 4 1

4 High idle speed after warm
up
1 4 3* 2

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

6 Runs rouah
on
deceleration
2 1

7 Afterburn
in
exhaust svstem
2 1

8 Poor fuel consumption
2 1 4 3

9 Fails emission test
6 4 5 3 2 1
Only MTX
76G04A-016
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
Engine
1) Compression
2) Overheating
Others
1) Clutch slippage
2) Brake dragging
2nd Check
the
Fuel
and
Emission Control Systems
4A—18

TROUBLESHOOTING GUIDE
4A

FE
12
VALVE and
F8
(EXCEPT MIDDLE EAST and 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)
PTC
heater
system

Air

injection
system
Positive
crankcase
ventilation
system
Deceleration
control
system

Idle-up

control
system

Ignition

control
system

POSSIBLE CAUSE
\ PAGE
SYMPTOM

4A-23 4A-60 4A-38 4A-24 4A-42 4A-58 4A-67 4A—45 4A—68 4 A—80
1 Hard start
or
won't start
(Cranks
OK)
1 2

2 Engine stalls During warm
up
5 4 1 6 2 3
2 Engine stalls After warm
up
3 2 4 1

3 Rough idle During warm
up
5 4 1 6 2 3
3 Rough idle After warm
up
3 2 4 1

4 High idle speed after warm
up
1 4 3 2

5 Poor acceleration, hesitation, or lack
of
power
1 4 2 3

6 Runs rough
on
deceleration
2 1

7 Afterburn
in
exhaust system
2 1

8 Poor fuel consumption
3 1 4 2
4
9 Fails emission test
6 2 5 3 1 4

76G04A-017
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
Engine
1) Compression
2) Overheating
Others
1) Clutch slippage
2) Brake dragging
2nd Check the Fuel
and
Emission Control Systems
4A—19

4A TROUBLESHOOTING GUIDE
FE and F8 (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
PTC
heater
system
Positive
crankcase

ventilation

system

Deceleration

control
system
POSSIBLE CAUSE
\ PAGE
SYMPTOM 4A-23 4A—60 4A—38 4A—24 4A—68 4A—42 4A—67 4A—45
1 Hard start or won't start (Cranks OK) 1 2
2 Engine stalls During warm up 5 4 1 6 2 3 2 Engine stalls After warm up 3 2 4 1
3 Rough idle During warm up 5 4 1 6 2 3 3 Rough idle After warm up 3 2 4 1
4 High idle speed after warm up 1 4 2 3
5 Poor acceleration, hesitation, or lack of power 1 4 3 2
6 Runs rough on deceleration 2 1
7 Afterburn in exhaust system 2 1
8 Poor fuel consumption 2 1 3
9 Fails emission test 3 2 4 1
76G04A-018
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
Engine
1) Compression
2) Overheating
Others
1) Clutch slippage
2) Brake dragging
2nd Check the Fuel and Emission Control Systems
4A—20

TROUBLESHOOTING GUIDE 4A
FE (MIDDLE EAST)
The Troubleshooting Guide lists the systems most likely to cause a given symptom. After finding the
system(s) to check, refer to pages shown for detailed guides for each system.
V. POSSIBLE CAUSE
\ PAGE
SYMPTOM

I
Air

cleaner

(Air

cleaner

element)

Intake

air

temperature

control

system

Idle

adjustment

Fuel

system

(Carburetor,

Fuel

pump)

Idle-up

control

system
Dashpot

(Only

MTX)

Positive

crankcase

ventilation

system
Exhaust
system

Evaporative

emission

control

system

Auto-return

choke

system

V. POSSIBLE CAUSE
\ PAGE
SYMPTOM 4A—23 4A-60 4 A—38 4A-24 4A-68 4A-50 4A-67 4A-96 4A-78 4A-40
1 Hard start or won't start
(Cranks OK) 1 2 3
2 Engine stalls During warm up 3 2 1 4 2 Engine stalls After warm up 3 2 4 1
3 Rough idle During warm up 3 2 1 4 3 Rough idle After warm up 3 2 4 1
4 High idle speed after warm up 1 5 3 4 2
5 Poor acceleration, hesitation, or lack of power 1 2 3
6 Runs rough on deceleration 2 1
7 Afterburn in exhaust system 3 1 2
8 Poor fuel consumption 5 1 6 2 3 4
9 Falls emission test 5 4 6 3 1 2
76G04A-019
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
Engine
1) Compression
2) Overheating
Others
1) Clutch slippage
2) Brake dragging
2nd Check the Fuel and Emission Control Systems
4 A—21

4A TROUBLESHOOTING GUIDE
FE 8VALVE—UNLEADED FUEL
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.
V POSSIBLE CAUSE
\ PAGE
SYMPTOM
Air

cleaner

(Air

cleaner

element)

Idle

adjustment

Fuel

system
(Carburetor,

Fuel

pump)
PTC

heater

system

Air

injection
system

Positive

crankcase

ventilation

system

Deceleration

control
system
Exhaust
gas

recirculation

(EGR)
system

Exhaust

system
Intake
air

temperature

control
system

Idle-up

control

system
Purge

control

system
Auto-return
choke
system
V POSSIBLE CAUSE
\ PAGE
SYMPTOM 4A-23 4A-38 4A-24 4A—42 4A-58 4A—67 4A—45 4A-96 4A-97 4A—60 4A—68 4A--63 4A—40
1 Hard start or won't start
(Cranks OK) 1 2
2 Engine stalls During warm up 6 1 2 5 3 4 2 Engine stalls After warm up 4 2 3 1
3 Rough Idle During warm up 5 1 2 4 3 6 3 Rough Idle After warm up 4 2 3 1
4 High idle speed after warm up 1 5 4 3 2
5 Poor acceleration, hesitation, or lack of power 1 2 5 3 4
6 Runs rough on deceleratio 2 1
7 Afterburn in exhaust system 2 1
8 Poor fuel consumption 4 1 2 3 5
9 Fails emission test 5 1 6 4 3 2
76G04A-020
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
Intake air system
1) Vacuum or air leakage
2) Vacuum hose routing
3) Accelerator cable
4) Choke cable
2nd Check the Fuel and Emission Control Systems
Ignition system
1) Spark plugs
2) Ignition timing
Engine
1) Compression
2) Overheating
Fuel system
1) Fuel level
2) Fuel leakage
3) Fuel filter
4) Idle speed
Others
1) Clutch slippage
2) Brake dragging
4A-22

DECELERATION CONTROL SYSTEM 4 A
SLOW FUEL CUT SYSTEM [FE 8VALVE—UNLEADED FUEL]
76G04A-096
This system shuts the primary slow fuel passage to prevent run-on and overheating of the exhaust
system when the ignition switch is turned OFF or during deceleration (engine speed above 2,300
rpm and idle switch ON). The slow fuel cut solenoid is actuated by the engine control unit and ignition
switch.
Troubleshooting
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting Guide. (Refer to page 4A—47.)
Possible cause System inspection Slow fuel cut solenoid valve
Page 4A—53 4A—34
Check order 1 2
System Inspection
1. Warm up the engine and run it at idle.
2. Connect a tachometer to the engine.
3. Connect a voltmeter to the carburetor connector
terminal (BW wire).
4. Increase the engine speed to 4,000 rpm; then re-
lease the throttle lever.
5. Measure the terminal voltage.
Engine speed Voltage
Above approx. 2,300 rpm Approx. 12V
Below approx. 2,300 rpm Below 1.5V
76G04A-097
4A-53

TROUBLESHOOTING GUIDE 4B
TROUBLESHOOTING GUIDE
This troubleshooting guide shows the malfunction numbers and the symptoms of various failures.
Perform troubleshooting as described below.
Possible cause
Symptom
Input sensors and switches
o> Q.
C
0
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4B-14
a> 4)
E
o
4B-1S
o in c « m o E k_ 0) c.
0 <0 £
4B-16
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a>
.x
co
4B-17
o 10 c a) co
4B-18
o in c a> (0
o> o> a>
a) £ a VI o E
4B-19
0 <0 c a> 0) c a> 01
S? o
4B-20
E a> in (0
o 10 A •o 0) 0> u.
4B-21
Output solenoid valves
o «
3 O) 0)
0) 0) 01
0> > 10 >
•o o c V o tt)
4B-22
0)
OI

0> > CO >

TJ
O c 0> o CO
4B-23
oc O u
o> > 75 >
•o o c a> o 05
4B-23
0 a. 3 1
2
0) > (0 >
"D O
o 0> in in a a >. £
4B-23
ffl a 3 • a>
2
a> > 10 >
"O o c a> o
CO Q. >. JO
4B-24
Fault Indicated by SST
Code No. 01 08 09 10 12 14 15 17 25 26 28 34 35
Hard start or won't start
(Cranks OK)
Engine stalls
Rough
idle
While warming up
After warming up
While warming up
After warming up
High idle speed after
warming up
TROUBLESHOOTING PROCEDURE
Note
Step 1 under symptom is to quickly determine what system or unit may be at fault by use of the SST. (Self-Diagnosis Checker 49 H018 9A1)
1st:
Check input sensors and output solenoid valves with the
SST.
(Refer
to
page 4B—10.)

2nd:
Check other switches with the
SST.
(Refer
to
page 4B—26.)

3rd:
Check the following items:

11
Poor acceleration, hesita-
tion or lack of power
Runs rough on deceleration
Afterburn in exhaust system
Poor fuel consumption
Engine stalls or rough after hot starting
Electrical system
1) Battery condition
2) Fuses

Fuel system
1) Fuel level 2) Fuel leakage
3) Fuel filter 4) Idle speed

Engine
1) Compression 2) Overheating

Ignition system

1) Ignition spark 2) Ignition timing

Intake air system
1)
Air
cleaner element 2) Vacuum
or air
leakage 3) Vacuum hose routing
4) Accelerator cable

Others
1) Clutch slippage 2) Brake dragging

Fails emission test 4th:
Check Fuel and Emission Control Systems. (Refer
to
page 4B—8.)

76G04B-003
4B—7

TROUBLESHOOTING GUIDE 4C
TROUBLESHOOTING GUIDE
This troubleshooting guide shows the malfunction numbers and the symptoms of various failures.
Perform troubleshooting as described below.
Input sensors and switches
Possible cause
Page
Symptom and No. CO
T O
a c OI '35
O
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o>
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o at e 0) o>
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Output solenoid valve
o> > <0 >
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—.

§8 £ c
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(0
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CVI I o
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"O o c a> o (/)
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Fault Indicated by SST
Code No. 02 03 05 *i 08 09 11 12 *2 15 • 2 17 *2 25 26 *2 27 *2 28 • 2 34 36 • 2 41
Hard start or won't start
(Cranks OK)
Engine stalls
Rough
Idle
During warm up
After warm up
During warm up
After warm up
High idle speed after warm up
Poor acceleration, hesita-tion or lack of power
TROUBLESHOOTING PROCEDURE
Note
Code No. Is to quickly determine which system or unit may be at fault by use of the SST. (Self-Diagnosis Checker 49 H018 9A1 or Digital Code Checker 49 G018 9A0 with Adaptor harness 49 9200 180)
1st: Check input sensors and output solenoid valves with the SST. (Refer to
page
AC—11.)

2nd: Check other switches with the SST. (Refer to page AC—25.)
3rd: Check the following items:
Electrical system
1) Battery condition 2) Fuses
Runs rough on deceleration
Afterburn in exhaust
system
9
10
Poor fuel consumption
Engine stalls or runs
rough after hot starting
11
12
Knocking
Fuel system
1) Fuel level
2) Fuel leakage 3) Fuel filter 4) Idle speed (with test connec-tor grounded)
Engine
1) Compression 2) Overheating
Ignition system 1) Ignition spark
2) Ignition timing (with test connec-tor grounded)
Intake air system 1) Air cleaner element 2) Vacuum or air leakage 3) Vacuum hose routing 4) Accelerator cable
Others 1) Clutch slippage
2) Brake dragging
Fails emission test 4th: Check Fuel and Emission Control Systems. (Refer to page 4C—10.)
*1..
*2„
.Leaded fuel
.Unleaded fuel
76G04C-009
4C—9