1987 MAZDA 626 water

4A OUTLINE
EMISSION COMPONENTS LOCATION
ECE, Hong Kong, and Singapore
Dashpot*
Reed valve
Solenoid valve*2 (Ignition timing control system)
Vacuum switch*5
Anti-afterburn valve
Choke opener
Idle-up solenoid valve^*5
or coasting leaner*6
Water thermo switch
Thermo valve*6
Water thermo switch
PTC heater*5
Air bypass solenoid valve*3
Solenoid valve*5
(Choke opener)
jr'-f
Choke breaker diaphragm
Solenoid valve*5 (Main air bleed control system)
Solenoid valve (P/S)*1
Solenoid valve (A/C)*1
Engine control unit
Fuel pump
*1 If equipped
*2 FE and F8 ATX
*3 F8 MTX and FE
*4 MTX
*5 FE and F8
*6 F6
76G04A-008
4A—8

General and Middle East
OUTLINE 4A
Dashpot
Choke opener
Thermo valve*3
Water thermo switch
Charcoal canister*3
Vacuum switch*2
Solenoid valve*2
(Main air bleed control system)
Solenoid valve (P/S)*1
Solenodi valve (A/C)*1
Engine control unit*2
Water thermo switch
*1 If euqipped
*2 FE and F8 General
*3 Middle East
*4 Middle East MTX
76G04A-009
4A-9

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

4 A AUTO-RETURN CHOKE SYSTEM
AUTO-RETURN CHOKE SYSTEM
[FE 8VALVE—UNLEADED FUEL, MIDDLE EAST, and F6—GENERAL]
r ~ I
76G04A-066
An auto-return choke is adopted to prevent the catalytic converter from over-heating because of over
use of the choke. This system opens the choke valve by causing the choke knob to return when the
engine coolant temperature is more than 67°C (153°F).
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 4A—16, 21, or 22)
Possible cause
" ^ Page
Symptom
System inspection Choke magnet Water thermo switch
Possible cause
" ^ Page
Symptom 4A—40 4A—41 4A—41
Checking order 1 2 3
76G04A-067
System Inspection
1. Make sure that the engine is cold and turn the ig-
nition switch ON.
2. Pull out the choke knob and check that it is held on.
3. Start the engine and check that the choke knob
returns during warming-up.
76G04A-068
4A—40

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

4A PTC HEATER SYSTEM
PTC HEATER SYSTEM
[FE
and
F8 engine (except Middle
East)]
76G04A-071
The PTC heater system consists of the PTC heater, relay, and water thermo switch. The system is
designed to prevent carburetor icing when the engine operating temperature is low t assure optimum
driveability.
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 4A—19, —20, or—22)
FE 8Valve—Unleaded Fuel
Possible cause System
inspection
Water thermo switch (intake manifold)
PTC heater
Water
thermo
switch
(Radiator)
PTC heater
relay
Page 4A—43 4A—41 4A—43 4A—95 4A—44
Checking order 1 2 3 4 5
Except FE 8Valve—Unleaded Fuel
Possible cause System inspection
Water thermo switch (Radiator)
PTC heater PTC heater
relay
Page 4A—43 4A—95 4A—43 4A—44
Checking order 1 2 3 4
76G04A-072
4A-42

DECELERATION CONTROL SYSTEM 4 A
MAIN AIR BLEED CONTROL SYSTEM
FE and F8 (ECE, Hong Kong, Singapore, and General)
Primary
Air/Fuel mixture—Lean Air/Fuel mixture—Rich
76G04A-093
This system prevents the additional air from being fed to the primary air bleed circuit and causes the
air/fuel mixture to become rich, improving acceleration.
Troubleshooting
Possible cause System inspection Solenoid valve Vacuum switch Water thermo
switch (Radiator)
Page 4A—52 4A—52 4A—94 4A—95
Checking order 1 2 3 4
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting. (Refer to pages 4A—46 or —47.)
4A—51

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