check engine MAZDA 626 1987 Repair Manual

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

FUEL SYSTEM 4A
TROUBLESHOOTING
POSSIBLE CAUSE
\ PAGE Carburetor Fuel pump Separator
Two-way check valve (Except Middle East) Three-way check valve (Middle East)
SYMPTOM 4A—26 4A—35 4A—37 4A—37
1 Hard start or won't start (Cranks OK) 2 1
2 Engine stalls During warm up 2 1 2 Engine stalls After warm up 2 1
3 Rough idle During warm up 2 1 3 Rough idle After warm up 2 1
4 High idle speed after warm up 1
5 Poor acceleration, hesitation, or lack of power 2 1
6 Runs rough on deceleration 1
7 Afterburn in exhaust system 1
8 Poor fuel consumption 1 2 3
9 Fails emission test 1
76G04A-026
4A-25

4A FUEL SYSTEM
CARBURETOR
Removal
Remove in the sequence shown in the figure.
1. Secondary air hoses (If equipped) and air
cleaner
2. Water hoses
3. Fuel hose
4. Vacuum hoses
76G04A-027
5. Accelerator cable
6. Connector
7. Carburetor
8. PTC heater (If equipped)
9. Gasket (If equipped)
Installation
Install the reverse order of removal, referring following points.
1. Check for fuel leaks.
2. Check the vacuum hose installation.
3. Check the idle speed and idle mixture (Refer to page 4A—38).
4. Warm up the engine to the normal operating temperature and check that fuel level is at the center
of the float level indicator window.
4A—26

FUEL SYSTEM 4A
76G04A-040
76G04A-041
Clearance
® J t'YCL ® J
V hi /®
'-v
76G04A-042
Fast Idle Opening
FE and F8 (General, ECE, Hong Kong, and Sin-
gapore)
Adjustment of fast idle opening is normally un-
necessary.
But if it is necessary, adjust it as shown.
1. Before adjustment, let the carburetor set at 25WC
(77°F) for at least 1 hour.
2. Check that the center of the cam lever aligns with
the mark (25°) on the fast idle cam.
3. If not as specified, adjust it by turning the adjust
screw.
4. Measure the throttle valve clearance between the
throttle valve and wall with a wire gage.
Specification
Spec. General, ECE, Hong Kong,
and Singapore
Transmission MTX ATX
Clearance mm (in) 0.48—0.64
(0.019-0.025)
0.56—0.72 (0.022-0.028)
5. If not as specified, adjust it by turning the fast idle
adjust screw.
Unloader System
Only FE and F8 (General, ECE, Hong Kong, and
Singapore)
1. Open the primary throttle valve fully.
2. Measure the choke valve clearance.
Clearance-
1.68—2.14 mm (0.066—0.084 in)
3. If not as specified, adjust it by bending tab A.
Slow Fuel Cut Solenoid Valve
1. Start the engine, and run it at idle.
2. Disconnect the connector of the carburetor.
3. Check that the engine stops.
4. If the engine does not stop, replace the slow fuel
cut solenoid valve.
76G04A-043
4A-33

FUEL SYSTEM 4 A
76G04A-048
76G04A-049
FUEL PUMP
Inspection
Fuel pressure
1. Disconnect the hose at the carburetor and connect
a fuel pressure gauge.
2. Disconnect the fuel return hose from the fuel pump
and plug the fuel pump return pipe as shown in
the figure,
3. Measure the pressure while the engine is idling.
Replace the pump, if necessary.
FE & F8 (ECE,
Hong Kong,
Singapore)
Others
Pressure kPa
(kg/cm2, psi)
20—29 (0.2-0.3, 2.8-4.3)
20-26
(0.20-0.27,
2.8-3.8)
Flow rate (volume)
1. Disconnect the carburetor fuel hose and insert the
end into a measuring breaker.
2. Disconnect the fuel return hose from the fuel pump
and plug the fuel pump return pipe as shown in
the figure.
3. Start the engine and measure the amount of fuel
pumped per minute.
Volume: More than 860 cc (52.5 cuin)/min
Removal
1. Remove in the following order.
(1) Fuel outlet hose
(2) Fuel inlet hose
(3) Fuel return hose
(4) Fuel pump
(5) Gasket
(6) Insulator
(7) Gasket
76G04A-050
Installation
Install in the reverse order of removal.
Caution
a) Replace the gasket whenever the fuel pump
is replaced.
b) Be sure to connect the hoses in the correct
positions.
Check for leaks.
76G04A-051
4A—35
expert22 fl/i* http://rutracker.org

4A
IDLE
SPEED AND
IDLE
MIXTURE
76G04A-059
76G04A-060
76G04A-061

IDLE
SPEED AND IDLE MIXTURE
ADJUSTMENT
Note
a) Before adjusting the idle speed and idle
mixture, be sure the ignition timing, spark
plugs, carburetor float level, etc., are all in
normal operation condition.
b)Turn off all electrical loads.
c) This adjustment must be done while the fan
motor is not operating.
Idle Speed
1. Connect a tachometer to the engine.
2. Warm up the engine, and check that the choke
valve has fully opened.
3. Check the idle speed.
Specification
MTX ATX (in N range)
Specification Others
FE 8Valve Unleaded fuel F6 F8 & FE
Idle speed rpm 800 +6S 850 +5S 950 +5o° 900 +5§
4. If not within specification, adjust the idle speed by
turning the throttle adjust screw.
Caution
After adjusting the idle speed, the dashpot ad-
justment should be checked and adjusted if
necessary.
Idle Mixture
[Except FE 8Valve—Unleaded Fuel]
Adjust the idle mixture as follows, after adjusting the
idle speed.
1. Disconnect the secondary air hoses from the reed
valves and plug them. (If equipped.)
2. Insert an exhaust gas analyzer into the tail pipe and
measure the CO concentration.
CO concentration: 2.0 ± 0.5%
3. If not within the specification, remove the blind cap
from the mixture adjust screw.
76G04A-062
4A—38