1987 MAZDA 626 coolant

AUTO-RETURN CHOKE SYSTEM 4A
Choke Magnet
1. Remove the under dash cover.
2. Disconnect the choke magnet connector.
3. Turn the ignition switch on and check the resistance
using an ohmmeter.
Resistance: Approx. 3512
4. If it is not within the specification, the choke mag-
net is malfunction.
76G04A-069
76G04A-070
Water thermo switch
1. Remove the switch from the intake manifold.
2. Place the switch in a container of water with a ther-
mometer.
3. Connect an ohmmeter to the switch.
4. Heat the water slowly and check that the switch
has continuity at 67°C (152°F).
5. Replace if necessary.
Note
a) Apply sealing tape to the threads of the
switch.
b) After installing, check the coolant level and
check for leaks.
4A—41

PTC HEATER SYSTEM 4A
System Inspection
Except FE 8Valve—Unleaded Fuel
1. Connect a voltmeter to the PTC heater connector.
2. Start the engine and measure the voltage.
Specification
Radiator coolant
temperature Below 17°C (63°F) Above
17°C (63°F)
Voltage Approx. 12V ov
76G04A-073
FE 8Valve—Unleaded Fuel
1. Start the engine.
2. Connect a voltmeter to the PTC heater connector
terminals and measure the voltage.
Voltage
Engine coolant
temperature
Below 67°C (152°F)
Above 67°C (152°F)
Radiator coolant temperature Below 17°C (63°F) Above 17°C (63°F) —
Terminal BrB Approx.
12V
OV OV Terminal BrW
Approx.
12V Approx. 12V OV
76G04A-074
PTC Heater
Except FE 8Valve—Unleaded Fuel
1. Disconnect the PTC heater connector.
2. Check for continuity of the heater with an
ohmmeter.
76G04A-075
FE 8Valve—Unleaded Fuel
1. Disconnect the PTC heater connector.
2. Check for continuity between terminal wire (BrW)
and a ground.
3. Check for continuity between terminal wire (BrB)
and (B).
76G04A-076
4A—43

4 A DECELERATION CONTROL SYSTEM
Solenoid valve (for main air bleed control system)
76G04A-094
76G04A-095
76G04A-191
System Inspection
1. Disconnect the vacuum switch connector.
2. Make sure that radiator coolant temperature is be-
low 17°C (63°F).
3. Disconnect the upper vacuum hose from the sole-
noid valve.
4. Place a finger over the solenoid valve open port
and check that vacuum is not felt when engine is
running.
5. Warming up the engine.
6. Place a finger over the same open port of the sole-
noid valve and check that weak vacuum is felt.
7. Reconnect the vacuum switch connector.
8. Check that weak vacuum is felt at the open port
of the solenoid valve at idle.
9. Accelerate the engine rapidly and check that vacu-
um is not felt.
Solenoid Valve (A/C)
1. Disconnect vacuum hose A (White) from the car-
buretor.
2. Disconnect vacuum hose B from the solenoid
valve.
3. Disconnect the solenoid valve connector.
4. Blow air through the valve from hose A and check
that it comes out of port C.
5. Apply 12V and ground to the solenoid valve with
jumper wires.
6. Blow air through the valve from hose A and check
that air not come out.
7. Replace if necessary.
76G04A-192
4A—52

PURGE CONTROL SYSTEM 4 A
PURGE CONTROL SYSTEM
[FE 8VALVE—UNLEADED FUEL]
Vaccum switch valve -4
I
Water thermo valve
76G04A-120
This system supplies additional air to the intake manifold to improve the driveability when the engine
coolant temperature is above 50°C (122°F).
TROUBLESHOOTING
Possible cause Vacuum switch valve Water thermo valve
Page 4A—63 4A—66
Checking order 1 2
VACUUM SWITCH VALVE
1. Connect a vacuum pump to the purge control
valve as shown in the figure.
2. Blow through the valve from port A and check that
air does not come out of port B.
3. Apply 100 mm-Hg (3.94 InHg) vacuum.
4. Blow through port A and check that air comes out
of port B.
5. Replace if necessary.
76G04A-121
4A-63

4A IDLE-UP CONTROL SYSTEM
IDLE-UP SOLENOID VALVE
FE and F8 (General, ECE, Hong Kong, and Singapore)
Water thermo switch Fan speed control switch Headlights _
Rear defroster
A/C
Engine1
control -
unit
Richer air bleed
Richer jet
/ '
Inhibitor switch
Water thermo switch Fan speed _ control switch Headlights -
Rear defroster —
A/C
Engine
control
unit
Idle-up solenoid valve
Adjust screw
Secondary
throttle valve
From secondary main jet
76G04A-151
The idle-up solenoid valve opens when the following conditions are met.
Condition
When inhibitor switch is OFF (ATX—other than "P" and "N" range) and any of the following:
• Engine coolant temperature less than 72°C (162°F).
• A/C operated.
• Fan speed control switch 3rd or 4th position.
• Headlights turned on.
• Rear defroster turned on.
4A—76

4 A IGNITION TIMING CONTROL SYSTEM
IGNITION TIMING CONTROL SYSTEM
F8 and FE (12-VALVE)—ATX (ECE, Singapore, and Hong Kong)
Ignition coil
76G04A-160
This system consists of the distributor, solenoid valve, and several switches, vacuum to the vacuum
control unit of the distributor is cut when the conditions below are met.
Item Condition
Engine speed Below 2,300 rpm
Selector lever position Other than P and N range
Coolant temperature Engine coolant: below 72°C (162°F) Radiator coolant: above 17°C (65°F)
4A—80

4A CONTROL SYSTEM
ENGINE CONTROL UNIT
Check the engine control unit terminal voltages with
a voltmeter.
Caution
a) Warm up the engine before checking the
control unit.
b) If the proper voltage is not obtained, check
the wiring, connections and finally, check
the component.
FE and F8 Engine — ATX (ECE, Hong Kong, and Singapore)
Terminal
(Wire color) Connected to Condition Voltage

1A
(BW)
Ignition switch Ignition switch ON. Battery voltage

m
ST
'-O
Solenoid valve (Main
air
bleed control) Others Battery voltage
m
ST
'-O
Solenoid valve (Main
air
bleed control) Radiator coolant temperature below 17°C (63°F)
or
intake manifold vacuum more than 200 mmHg (7.9 inHg)
Below 1,5V
1C (GO) Solenoid valve (Choke opener) Radiator coolant temperature below 17°C (63°F)
or
during cranking and
27
sec. after engine starts Below 1,5V
Others Battery voltage
1D
(GL)
Air bypass solenoid valve Idle switch OFF and engine speed above approx. 2,100 rpm Below 1,5V
Others Battery voltage
1E
— — —

1F
(G) Solenoid valve (Ignition timing control system)
Radiator coolant temperature above 17°C (63°F),
en-
gine coolant temperature below 72°C (162°F), inhibi-tor switch OFF and engine speed below 2,300
rpm

Below 1.5 V
Others Battery voltage
1G
— — —

1H
(LW) Solenoid valve (A/C) A/C switch
ON
and engine speed below approx. 2,300
rpm

Below 1,5V
Others Battery voltage
11
(YW) Idle-up solenoid valve Inhibitor switch OFF and, headlight switch ON, rear
defroster switch ON, fan speed control switch
is 3rd

or 4th position, A/C operated,
or
engine coolant tem-
perature below 72°C (162°F)
Below 1,5V
Others Battery voltage
1J
(B)
Ground
—
Below 1,5V

9 MSSirSl
ivj
A 1
k *
76G04A-169
4A—86

CONTROL SYSTEM 4 A
Terminal
(Wire color) Connected to Condition Voltage

2A
(YL)
Ignition coil Ignition switch
ON or
engine running Battery voltage
2B (LB) Fan speed control switch Fan speed control switch
in
3rd
or
4th position Below 1.5 V 2B (LB) Fan speed control switch
Fan speed control switch OFF Battery voltage
2C
(BL)
Rear defroster switch Rear defroster switch
ON
Below 1,5V 2C
(BL)
Rear defroster switch
Rear defroster switch OFF Battery voltage
2D
(LG)
A/C switch A/C operated Below 1,5V 2D
(LG)
A/C switch
A/C not operated Battery voltage
2E
(RG)
Headlight switch Headlight switch OFF Below 1.5 V 2E
(RG)
Headlight switch
Headlight switch
ON
Battery voltage
2F
(GW)
Water thermo switch
(Radiator)
Radiator coolant temperature below 17°C (63°F) Below 1.5V 2F
(GW)
Water thermo switch
(Radiator) Radiator coolant temperature above 17°C (63°F) Battery voltage
2G
-— —

2H
(L)
Water thermo switch (In-
take manifold)
Engine coolant temperature below 72°C (162°F) Below 1,5V 2H
(L)
Water thermo switch (In-
take manifold) Engine coolant temperature above 72°C (162°F) Battery voltage
21
(LY)
Vacuum switch Vacuum less than 200 mmHg (7.9 inHg) Below 1.5V 21
(LY)
Vacuum switch
Vacuum more than 200 mmHg (7.9 inHg) Battery voltage
2J (RL) OD release solenoid valve Engine coolant temperature below 72°C (162°F) Below 1.5V 2J (RL) OD release solenoid valve
Engine coolant temperature above 72°C (162°F) Battery voltage
2K
(-)

— — -

2L (BR)
Inhibitor switch "N"
or "P"
range Below 1.5V 2L (BR)
Inhibitor switch
Others Battery voltage
2M (BY) Ignition switch
(START position)
Ignition switch
ON
Below 1,5V 2M (BY) Ignition switch
(START position) Cranking Battery voltage
2N
(LsB) Idle switch Idling Battery voltage 2N
(LsB) Idle switch
Accelerator pedal depressed Below 1,5V

76G04A-170

{ 2M 2K 21
X
2F 2C
2A

2N 2L 2J 2H 2F 2D 2B
(11 X X
1C 1 A^j
1J 1H 1F 1D 1B

FE and F8 Engine — MTX (ECE, Hong Kong, and Singapore)
Terminal (Wire color) Connected to Condition Voltage

A
(RG) Headlight switch Headlight switch
ON
Below 1,5V A
(RG) Headlight switch
Headlight switch OFF Battery voltage
B
(B)
Ground
—
Below 1,5V

4A-87