1987 MAZDA 626 temperature

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

4 A INTAKE AIR TEMPERATURE CONTROL SYSTEM
INTAKE AIR TEMPERATURE CONTROL SYSTEM
76G04A-112
This system controls air intake temperature to prevent icing and operates depending on air tempera-
ture around the control valve.
TROUBLESHOOTING
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting Guide. (Refer to pages from 4A—17 to 4A—22.)
FE and F8 (General, ECE, and Hong Kong) and Singapore
Possible cause
Symptom
System inspection Vacuum control
diaphragm
Intake air temperature control valve
Possible cause
Symptom 4A—61 4A—61 4A—61
Checking order 1 2 3
FE 8 Valve—Unleaded Fuel, Middle East, and F6—General
Possible cause System inspection
Page 4A—62
Checking order 1
76G04A-113
4A-60

INTAKE AIR TEMPERATURE CONTROL SYSTEM 4A
76G04A-114
76G04A-115
Intake air temperature
control valve
System Inspection
[Except Manual and Bimetal Type]
1. Disconnect the vacuum hose from the vacuum
control diaphragm.
2. Start the engine and check that vacuum is felt while
the engine is still cold.
3. Warm up the engine to the normal operating tem-
perature and check that vacuum is not felt.
Vacuum Control Diaphragm
1. Remove the air cleaner.
2. Connect the vacuum pump to the vacuum control
diaphragm.
3. Apply 160 mmHg (6.3 inHg) vacuum and check
that the shutter valve is opened to the hot position.
4. Replace the air cleaner if necessary.
Intake air temperature control valve
1. Check that the valve is closed when the bimetal
temperature is lower than specified.
Operating temperature: 30°C (86°F)
76G04A-116
C
E
75 O) o. .EE E~
—
c
60 |—c-(15.7, 13.2)
30 Z
%
(7.9, 6.61

O o>

cw
E <
Max
/Min.
20(68) 40(104) 60(140) 80(176)
Termperature °C (°F)
2. To check, suck air through the tube. If excessive
air leakage is found, replace the valve as an as-
sembly.
3. Check that the valve opens when heated.
4. Replace if necessary.
76G04A-116
4A—61

4A INTAKE AIR TEMPERATURE CONTROL SYSTEM
System Inspection
Bimetal type
[FE 8Valve—Unleaded Fuel]
Move the control valve inside the air cleaner, and
check that it moves freely and that spring force is felt.
System Inspection
Manual type
[Middle East and F6—General]
Change the summer-winter change lever and check
that it moves smoothly.
76G04A-119
4A—62

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