sensor MAZDA 626 1987 Service Manual

4B CONTROL SYSTEM
AIR FLOW METER
Potentiometer
Intake air thermo
sensor Fc EI E2 VB VC VS THA
Fuel pump switch
Connector-—
I
lOQDOQOD i
69G04C-100
Inspection
1. Remove the air flow meter. (Refer to page 4B—31)
2. Check the air flow meter body for cracks.
3. Verify that the measuring plate moves smoothly.
4. Disconnect the connector from the air flow meter.
5. Using an ohmmeter, check resistance between the
terminals with the measuring plate fully closed and
fully open.
6. Connect the connector to the air flow meter after
inspecting.
76G04B-112
Terminal Resistance (Q) Terminal Fully closed | Fully open
E2<->VS More than 20
E2«VC 100-300
E2«VB 200-400
E2«THA (Intake air thermo sensor)
-20°C (—4°F) 13.6-18.4 kfi 20°C (68°F) 2.21-2.69 kfi 60°C (140°F) 493—667 0
Ei<->Fc OO 0
Note
Refer to page 4B—31 for replacement of the
air flow meter.
76G04B-113
4B—94

CONTROL SYSTEM 4B
76G04B-114
c jr y—

D
'
CO CO

76G04B-115
76U04A-018
THROTTLE SENSOR
Inspection of Terminal Voltage
1. Remove the rubber boot from the connector.
2. Turn the ignition switch ON.
3. Check voltage between each terminal and a
ground.
4. Open the throttle valve and again check voltage
between each terminal and a ground.
Condition
Terminal Closed Fully open
A(Vt) 0.4—0.6V Approx. 4.0V
B (GND) Below 1.5 V
C (V ref) 4.5—5.5 V
D (IDL) Below 1.5 V Approx. 12 V
5. If not correct at the D terminal only, check the throt-
tle sensor setting.
6. If not correct on other terminals, check resistance
at the throttle sensor (Refer to page 4B—97) and
terminals (2A, 2C, 1E and 2G) (Refer to page
4B—88 and 89) of the engine control unit and wir-
ing harness.
7. Install the rubber boot on the connector.
Throttle Sensor Setting
Inspection
1. Disconnect the connector from the throttle sensor.
2. Connect the SST to the throttle sensor or connect
an ohmmeter between terminals B and D.
76G04B-116
4B-95

4B CONTROL SYSTEM
y
/OTaWX 1
rx
Throttle stop screw
76G04B-117
76G04B-11E
Counter clockwise i i
Clockwise
76G04B-119
3. Place a feeler gauge between the lever and the
throttle stop screw and check that the SST buzz-
er sounds or that there is continuity between ter-
minals B and D.
Feeler gauge 0 mm (0 in) 0.7 mm (0.028 in)
Buzzer Sounds Does not sound
Lamp ON OFF
Continuity YES NO
4. If not correct, adjust the throttle sensor as outlined
below.
Adjustment
1. Disconnect the connector and connect the SST
to the throttle sensor.
2. Place a 0.40 mm (0.016 in) feeler gauge between
the lever and the throttle stop screw.
3. Loosen the two attaching screws.
4. Rotate the throttle sensor clockwise about 30°, then
rotate it counterclockwise until the buzzer sounds.
5. If it does not buzz, replace the throttle sensor.
6. If it does buzz, substitute the feeler gauge with a
0.55 mm (0.022 in) gauge
7. Check that the buzzer does not sound.
8. If it buzzes, repeat steps 3 to 7.
If it still buzzes, replace the throttle sensor.
9. Tighten the two attaching screws.
Note
Be careful not to disturb the throttle sensor
position when tightening the screws.
10. Open the throttle valve fully a few times; then
recheck the adjustment of the throttle sensor.
11. Disconnect the SST from the throttle sensor and
reconnect the connector.
76G04B-120
4B-96

4B CONTROL SYSTEM
A:
56G04B-038
j Water thermo
sensor
86U04A-202
86U04A-203
Inspection of Resistance
1. Disconnect the connector from the sensor.
2. Check resistance between the terminals as shown
in the table.
3. Open the throttle valve fully and check resistances
between terminals.
Terminal Closed Fully open
A « B Approx. 500 Q Approx. 4.5 kQ
B «- C 4-6 kQ
4.If not correct, replace the throttle sensor.
WATER THERMO SENSOR
Inspection
1. Remove the water thermo sensor from the cylin-
der head.
2. Place the sensor in water with a thermometer and
heat the water gradually.
3. Check resistance of the sensor with an ohmmeter.
Coolant Resistance
-20°C ( -4°F) 14.5-17.8 kQ
20°C ( 68°F) 2.2-2.7 kfi
40°C (104°R 1.0—1.3 kfi
60°C (140°F) 500—640 n
80°C (176°F) 280-350 Q
4. If not correct, replace the water thermo sensor.
WATER THERMO SWITCH
Inspection
1. Remove the switch from the radiator.
2. Place the switch in water with a thermometer, and
heat the water gradually.
3. Check for continuity of the switch with an
ohmmeter.
Coolant temp. Continuity
More than approx. 17°C (63°F) Yes
Less than approx. 17°C (63°F) No
76G04B-132 4. If not correct, replace the water thermo switch.
4B—97

4B CONTROL SYSTEM
76G04B-121
86U04A-206
Check connector; Green (6 pin)y
49 H018 9A1
OXYGEN SENSOR
Inspection of Output Voltage
1. Warm up the engine and run it at idle.
2. Disconnect the oxygen sensor connector.
3. Connect a voltmeter between the oxygen sensor
and ground.
4. Run the engine at 4,000 rpm until the voltmeter
indicates approx. 0.55V.
5. Increase and decrease the engine speed suddenly
several times. Check to see that when the speed
is increased the meter reads between 0.5V—1.0V,
and when the speed is decreased it reads between
0V—0.4V
6. If the voltmeter doesn't indicate as specified, re-
place the oxygen sensor.
Inspection of Sensitivity
Caution
Do not ground the test connector (Green,
1-pin).
1. Warm up the engine to the normal operating tem-
perature and run it at idle.
2. Connect the SST to the check connector.
76G04B-133
Monitor lamp
SELF-DIAGNOSIS CHECKER
MONITOR > o .000 /TT\' o
SELECT SW «
86U04A-208
3. Increase the engine speed to between 2,000 and
3,000 rpm, and check that the monitor lamp flash-
es for 10 seconds.
Monitor lamp: Flashes ON and OFF
more than 8 times/10 sec
4B—98

4B CONTROL SYSTEM
ATMOSPHERIC PRESSURE SENSOR
Inspection
1. Connect a voltmeter to the atmospheric pressure
sensor (D) terminal.
2. Turn the ignition switch on and take a voltage
reading.
Voltage: 3.5—4.5V at sea level
2.5—3.5V at high altitude
[2,000m (6,500 ft)]
3. Replace the sensor if necessary.
67U04X-154
4B—99

4C
FUEL AND EMISSION
CONTROL SYSTEMS
(FUEL INJECTION FE DOHC)
OUTLINE 4C— 2
COMPONENT APPLICATION 4C— 2
SYSTEM DIAGRAM 4C— 3
COMPONENT LOCATION 4C— 4
VACUUM HOSE ROUTING
DIAGRAM 4C— 7
SPECIFICATIONS 4C— 8
TROUBLESHOOTING GUIDE 4C— 9
TROUBLESHOOTING WITH SST.. 4C— 11
INSPECTION PROCEDURE 4C— 12
PRINCIPLE OF CODE CYCLE 4C— 13
CODE NUMBER 4C— 14
SWITCH MONITOR FUNCTION 4C— 25
INSPECTION PROCEDURE 4C— 26
IDLE ADJUSTMENT 4C— 29
IDLE SPEED 4C— 29
IDLE MIXTURE 4C— 30
INTAKE AIR SYSTEM 4C— 31
COMPONENT DESCRIPTION 4C— 31
REMOVAL 4C— 32
PARTS INSPECTION 4C— 33
REPLACEMENT 4C— 36
INSTALLATION 4C— 37
VARIABLE INERTIA CONTROL
(VIC) SYSTEM 4C— 39
COMPONENT DESCRIPTION 4C— 40
TROUBLESHOOTING 4C— 40
IDLE SPEED CONTROL
(ISC) SYSTEM 4C— 44
COMPONENT DESCRIPTION 4C— 45
TROUBLESHOOTING 4C— 46
REMOVAL 4C— 48
FUEL SYSTEM 4C— 49
COMPONENT DESCRIPTION 4C— 50
TROUBLESHOOTING 4C— 51
FUEL PRESSURE RELEASE AND
SERVICING FUEL SYSTEM 4C— 52
MULTI-PRESSURE TESTER 4C— 53
FUEL PUMP 4C— 56
PULSATION DAMPER 4C— 57
INJECTOR 4C— 57
TRANSFER PUMP CONTROL
SYSTEM 4C— 59
REPLACEMENT 4C— 60
FUEL TANK 4C— 65
PRESSURE REGULATOR
CONTROL (PRC) SYSTEM 4C— 68
COMPONENT DESCRIPTION 4C— 69
TROUBLESHOOTING 4C— 69
DECELERATION CONTROL
SYSTEM 4C— 72
COMPONENT DESCRIPTION 4C— 73
TROUBLESHOOTING 4C— 73
ELECTRONIC SPARK ADVANCE
(ESA) CONTROL SYSTEM 4C— 75
COMPONENT DESCRIPTION 4C— 76
TROUBLESHOOTING 4C— 76
EXHAUST GAS RECIRCULATION
(EGR) SYSTEM 4C- 77
COMPONENT DESCRIPTION 4C— 77
TROUBLESHOOTING 4C— 78
EVAPORATIVE EMISSION
CONTROL (EEC) SYSTEM 4C— 80
COMPONENT DESCRIPTION 4C— 80
TROUBLESHOOTING 4C— 81
POSITIVE CRANKCASE
VENTILATION (PCV) SYSTEM.... 4C— 86
COMPONENT DESCRIPTION 4C— 86
PCV VALVE 4C— 86
EXHAUST SYSTEM
(UNLEADED FUEL) 4C— 87
REMOVAL AND INSTALLATION.. 4C— 88
INSPECTION 4C— 88
EXHAUST SYSTEM
(LEADED FUEL) 4C— 89
REMOVAL AND INSTALLATION.. 4C— 90
CONTROL SYSTEM 4C— 91
RELATIONSHIP CHART 4C— 92
EGI MAIN FUSE 4C— 96
CONTROL RELAY 4C— 96
NEUTRAL SWITCH 4C— 97
CLUTCH SWITCH 4C— 97
P/S PRESSURE SWITCH 4C— 97
ENGINE CONTROL UNIT 4C— 98
E/L CONTROL UNIT 4C—102
AIR FLOW SENSOR 4C—103
THROTTLE SENSOR 4C—104
IDLE SWITCH 4C—106
WATER THERMO SWITCH 4C—106
WATER THERMO SENSOR 4C—107
OXYGEN SENSOR 4C—107
DISTRIBUTOR 4C—108
OXYGEN SENSOR HEATER 4C—109
KNOCK SENSOR 4C—109
INTAKE AIR THERMO SENSOR .. 4C—110
76G04C-001

4C OUTLINE
OUTLINE
COMPONENT APPLICATION
Item Unleaded fuel Leaded fuel
Air flow sensor (Hot wire type) O O
Dynamic chamber with vacuum chamber o o
INTAKE AIR SYSTEM Throttle body (Two bore) o o
Throttle sensor o X
Idle switch o o
Resonance chamber o o
VARIABLE INERTIA CONTROL SYSTEM o 0
IDLE SPEED CONTROL SYSTEM o o
Injector o o
Pressure regulator o o
Pulsation damper o o
FUEL SYSTEM Intank filter o o
Transfer pump 0 (4WS) O (4WS)
Transfer pump switch O (4WS) O (4WS)
Fuel pump control unit O (4WS) O (4WS)
PRESSURE REGULATOR CONTROL SYSTEM o o
Canister o x
EVAPORATIVE Three-way check valve o x
EMISSION CONTROL Two-way check valve X o SYSTEM Separator o o
Solenoid valves o x
EGR control valve o x
EGR SYSTEM EGR modulator valve o X
Solenoid valve o X
ELECTRONIC SPARK
ADVANCE CONTROL
SYSTEM
Igniter o o ELECTRONIC SPARK
ADVANCE CONTROL
SYSTEM Knock control function X o
Water thermo sensor o o
Water thermo switch o X
Intake air thermo sensor o o
Oxygen sensor o X
CONTROL SYSTEM Distributor o o CONTROL SYSTEM Ne signal o o
G signal o o
Clutch switch o o
Neutral switch o o
Knock sensor x o
FAIL-SAFE CONTROL SYSTEM o o
MONITOR FUNCTION o o
76G04C-002
4C—2

Fuel filter Solenoid valve *1 Solenoid valve *1
(No.2 purge control) (No.1 purge control)
Separator Three way
Injector
,Distributor
Fuel pump
In-take filter
Air flow sensor
Water thermo sensor
Knock sensor
switches
Intake air thermo sensor
— Water thermo switch *1 __ j—Ig. switch (ST) j_J,—lg. switch (ON) -A/C switch 'A/C magnet clutch P/S switch —Head light switch —Rear defroster switch —Cooling fun switch —Blower switch —Neutral and clutch
O) <
{/> H m
g >
o 3D >
^Throttle sensor *1
Air valve
Solenoid valve
(ISC)
EGR control valve *1
EGR modulator valve *1
0 1 CO
a *1...Unleaded fuel only
*2...Leaded fuel only
Oxygen
sensor *1
One-way check valve
Shutter valve actuator Catalytic
converter *1 Solenoid valve (VIC)
O c
m
o

4C OUTLINE
COMPONENT LOCATION
Input and Output Devices
Solenoid Solenoid Idle valve valve switch /nnA
Solenoid
valve*1 Solenoid valve*1
'(No.1 purge control)
E/L control unit
Engine control unit
Control relay
Knock sensor*2
Water thermo
switch*1
Oxygen Distributor
sensor*1
Clutch switch
\ Oxygen sensor
\ relay*1
Solenoid valve*1 (EGR)
Solenoid valve (ISC)
Air flow sensor
Neutral switch
Water thermo sensor
*1...Unleade fuel only
*2...Leaded fuel only
76G04C-004
4C—4