1987 MAZDA 626 ignition

1 B ON-VEHICLE INSPECTION
76G01B-017
86U01X-020
76G01B-018
Possible Cause
ON-VEHICLE INSPECTION
If the engine exhibits low power, poor fuel economy,
or poor idle, check the following points.
1. Ignition system (Refer to Section 5)
2. Compression
3. Fuel system (Refer to Section 4C)
COMPRESSION
1. Check that the battery is fully charged. Recharge
if necessary.
2. Warm up the engine to the normal operating tem-
perature.
3. Turn it off for about 10 minutes to allow the exhaust
manifold to cool.
4. Remove all spark plugs.
5. Disconnect the primary wire connector from the
ignition coil.
6. Connect a compression gauge to No.1 spark plug
hole.
7. Fully depress the accelerator pedal and crank the
engine.
8. Note the maximum gauge reading.
9. Check each cylinder.
Standard compression:
1,422 kPa (14.5 kg/cm2, 206 psi)—290 rpm
Leaded fuel
1,373 kPa (14.0 kg/cm2,199 psi)—310 rpm
... Unleaded fuel
Compression limit:
996 kPa (10.2 kg/cm2, 144 psi)—290 rpm
Leaded fuel
961 kPa (9.8 kg/cm2, 139 psi)—310 rpm
... Unleaded fuel
If compression is low, pour heavy oil into the cylinder and turn the crankshaft several times Check compression once more
»
Is compression increased? Yes 1. Worn piston or piston rings
2. Worn cylinder wall
No
1. Worn piston or piston rings
2. Worn cylinder wall
No 1. Defective cylinder head gasket 2. Distorted cylinder head
Is compression in adjacent cylinder low? Yes
1. Defective cylinder head gasket 2. Distorted cylinder head
Is compression in adjacent cylinder low?
No 1. Improper valve seating
2. Valve sticking in guide
3. Defective cylinder head gasket
86U01X-022
1B—10

1B INSTALLATION
76G01B-113
76G01B-114
76G01B-115
Radiator
1. Install the radiator and cooling fan.
Tightening torque:
8—11 N-m (80—110 cm-kg, 69—95 in-lb)
2. Connect the radiator harness.
3. Connect the upper and lower radiator hoses.
Note
a) Position the hose clamp in the original lo-
cation on the hose.
b) Squeeze the clamp lightly with large pliers
to ensure a good fit.
Heater Hose and Fuel Hose
Connect the heater hoses and the fuel hoses.
High-Tension Lead
Connect the high-tension lead to the ignition coil.
Accelerator Cable
Install the accelerator cable.
76G01A-148
Battery and Battery Carrier
1. Install the battery carrier.
Tightening torque:
9—13 N-m (90—130 cm-kg, 78—113 in-lb)
2. Install the fuse box.
Tightening torque:
8—11
N
m (80—110 cm-kg, 69—95 in-lb)
3. Install the battery tray and battery.
Tightening torque:
5_7
N m
(50—70 cm-kg, 43—61 in-lb)
1B—80

3A COOLING FAN
COOLING FAN
SYSTEM CIRCUIT
IG1 IG Relay
*
No.1
relay
Water thermo switch
I With A/C

CM)
Main fan
1
L..±
No.2
relay
IG2
Add.
relay ol
(M)
A/C sw.
Add fan
86U03X-019
CIRCUIT INSPECTION
1. Turn the ignition switch ON.
2. Disconnect the water thermo switch connector, and
check that the fan operates.
3. If the fan doesn't operate, check the fuse, fan re-
lay, fan motor, thermo switch and wiring harness.
76G03A-010
3 A—12

3A 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.
76G03A-013
76G03A-014
Place the water thermo switch in water.
Heat the water gradually, and check for continui-
ty of the switch with an ohmmeter. Replace if
necessary.
Water thermo switch (ON OFF):
97°C (207°F)....ECE, Hong Kong, Singapore

91
°C (196°F)....General, Middle East
Install the water thermo switch and a new O-ring.
Caution
Do not use sealing tape.
3 A—14

3B COOLING FAN
COOLING FAN
SYSTEM CIRCUIT
I
IG1 IG Relay Main fuse
©
Main fan motor
V-f motor
IG1
Water thermo switch OFF: over 91°C (208 °F)
Water thermo switch ON:
below 84°C
(183°F)
76G03B-015
CIRCUIT INSPECTION
1. Turn the ignition switch ON.
2. Disconnect the water thermo switch connector, and
check that the fan begins to operate.
3. If the fan doesn't operate, check the fuse, fan re-
lay, fan motor, thermo switch, and wiring harness.
76G03B-016
3B—10

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