fuel MAZDA 626 1987 Repair Manual

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

4A FUEL SYSTEM
FUEL SYSTEM
This system consists of the fuel pump, fuel filters, and carburetor, and supplies the necessary fuel for
operation of the engine.
76G04A-025
4A—24

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
Disassembly
FE and F8 (General, ECE, Hong Kong, and Singapore)
76G04A-028
Disassemble in the sequence shown in the figure.
1. Lever
2. Secondary diaphragm
3. Choke breaker diaphragm and thermo wax
(If equipped)
4. Choke opener and bracket (If equipped)
5. Air horn
6. Float
7. Needle valve
8. Accelerator pump
9. Slow fuel cut solenoid valve
10. Idle-up solenoid valve and idle switch
(If equipped)
11. Air bleeds and jets
12. Injector weight
13. Primary venturi and nozzle
14. Secondary venturi and nozzle
15. Main body
16. Throttle body
4A—27

4A FUEL SYSTEM
FE 8Valve (Except General) and F6
76G04A-029
Disassemble in the sequence shown in the figure.
1. Lever 8. Solenoid valve* and idle switch (If equipped)
2. Air horn, choke breaker diaphragm, and 9. Air bleeds and jets
choke opener (If equipped) 10. Injector weight
3. Float 11. Primary venturi and nozzle
4. Secondary diaphragm 12. Secondary venturi and nozzle
5. Needle valve 13. Main body
6. Accelerator pump 14. Throttle body
7. Slow fuel cut solenoid valve
* Solenoid valve:
Coast enrichment solenoid valve FE 8 Valve—Unleaded fuel
Coasting leaner F6 Singapore
4A-28

FUEL SYSTEM 4 A
Assembly [FE and F8 (General, ECE, Hong Kong, and Singapore)]
Assemble in the sequence shown in the figure, referring to the assembly note for specially marked parts.
1. Throttle body
2. Main body
3. Secondary ven-
turi and nozzle
4. Primary venturi
and nozzle
5. Injector weight
Q. Air bleeds and
jets
7. Idle-up solenoid
valve and idle
switch (If
equipped)
8. Slow fuel cut
solenoid valve
9. Accelerator
pump
10. Needle valve
11. Float
12. Air horn
13. Choke opener
and bracket (If
equipped)
14. Choke breaker
diaphragm and
thermo wax (If
equipped)
15. Secondary di-
aphragm
16. Lever
76G04A-030
Assembly note
Air bleeds and jets
1. Step jet and plug
2. Secondary step air bleed (No. 1) (Fixed type)
3. Secondary main air bleed
4. Secondary main jet
5. Power jet
6. Primary main jet
7. Primary main air bleed
8. Primary slow air bleed (No. 1)
9. Primary slow jet and plug
10. Primary slow air bleed (No. 2)
76G04A-031
4A—29

4A FUEL SYSTEM
[FE 8Valve (Except General) and F6]
Assemble in the sequence shown in the figure, referring to the assembly note for specially marked parts.
1. Throttle body
2. Main body
3. Secondary ven-
turi and nozzle
4. Primary venturi
and nozzle
5. Injector weight
©Air bleeds and
jets
7. Solenoid valve
and idle switch
(If equipped)
8. Slow fuel cut
solenoid valve
9. Accelerator
pump
10. Needle valve
11. Secondary di-
aphragm
12. Float
13. Air horn, choke
breaker di-
aphragm, and
choke opener (If
equipped)
14. Lever
'3
©
76G04A-032
Assembly note
Air bleeds and jets
1. Step jet and plug
2. Secondary step air bleed (No. 1) (Fixed type)
3. Secondary main air bleed
4. Secondary main jet
5. Power jet
6. Primary main jet
7. Primary main air bleed
8. Primary slow air bleed (No. 1)
9. Primary slow jet and plug
10. Primary slow air bleed (No. 2)
76G04A-033
4A-30

FUEL SYSTEM 4A
76G04A-034
Inspection
Note
a) Clean all parts with carburetor cleaner and
dry with compressed air.
b) Do not use a wire to clean the jets.
Check the following and replace any faulty parts.
1. Damaged air horn, main body, or throttle body
2. Improper operation of the choke valve or throttle
valve
3. Damaged float
4. Needle valve damage or improper seating
5. Clogged or damaged jet or air bleed
6. Damaged piston cup in the accelerator pump
7. Weakened or broken spring
8. Damaged diaphragm
9. Improper solenoid operation
76G04A-191
Primary throttle valve
(0.248—0.327 in)
When secondary throttle valve
begins to open
Secondary Throttle Valve
1. Check the clearance between the primary throttle
valve and wall when lever A contacts lever B.
>
L_ Clearance:
7.3—8.3 mm (0.248—0.327 in)
7.3—8.3 mm
76G04A-035
3. If not within specification, adjust it by bending
lever A.
76G04A-036
4 A—31