1987 MAZDA 626 light

CONTROL SYSTEM 4C
Terminal Voltage
If the input and output devices wiring are normal, but the engine control unit terminal voltage is incor-
rect, replace the engine control unit.
Terminal Input Output Connection to Voltage (After warming-up) Remark Terminal Input Output Connection to Ign: ON Idle Remark
1A — — — — — —
1B o Self-Diagnosis Checker (Code No.)
For 3sec. after ignition switch OFF ->• ON: below 2.5V (Buzzer sounds) After 3sec.: approx. 12V (Buzzer does not sound)
• Using Self-Diagnosis Check-er and test con-nector grounded • Buzzer sounds: below 2.5V • Buzzer does not sound: approx. 12V
1C o
Solenoid valve (Variable inertia control) Approx. 12V
Above 5200 rpm (Unleaded fuel) or 5400 rpm (Leaded fuel): Below 2.5V
1D o Self-Diagnosis Checker (Monitor lamp)
For 3sec.after igni-tion switch OFF -» ON:
approx. 5V (light il-luminates)
After 3sec.: approx. 12V (light does not illuminate)
(Test connector grounded) approx. 5V (Test connector not grounded) Monitor lamp ON: approx. 5V Monitor lamp OFF: approx. 12V
With Self-Diagnosis
Checker
1E O Idle switch Accelerator pedal released: OV
Accelerator pedal depressed: approx. 12V
1F o A/C relay A/C switch ON: below 2.5V
A/C switch OFF: approx. 12V Blower motor ON
1G O Neutral or clutch switch
In-gear condition Clutch pedal depressed: approx. 12V Clutch pedal released: OV
MTX (Neutral: con-stant approx. 12V)
1H
(U/F) o Water thermo
switch
Approx. 12V Radiator temp.: be-low 17°C (63°R 1H
(U/F) o Water thermo
switch OV Radiator temp.:
above 17°C (63°F)
11 o Electrical load control unit E/L switch ON: below 2.5V
E/L switch OFF: approx. 10—12V
Electrical load: Rear defroster switch
Headlight switch Blower motor switch (3rd & 4th position) Electrical fan switch
1J — — — — —
1K o P/S pressure
switch
Constant approx.
12V
P/S ON: below 2.5V P/S OFF: approx. 12V
1L o A/C switch A/C switch ON: below 2.5V A/C switch OFF: aDDrox. 12V Blower motor: ON
1M o Distributor
(Ne signal) OV or 5V Approx. 2.0V
1N o Distributor (G signal) OV or 5V Approx. 1.2V
Note
Terminals labeled "U/F" are only for unleaded fuel.
4C-99

4C CONTROL SYSTEM
Terminal Input Output Connection to Voltage (After warming-up) Remark Terminal Input Output Connection to Ign: ON Idle Remark
10 o Air flow sensor
(Burn-off control) Below 2.5V White burning off:
Approx. 8—12V
1P o
Control relay (Power supply circuit) Below 2.5V Ignition switch OFF:
Approx. 12V
1Q 0 Control relay (Fuel pump circuit) Approx. 12V Below 2.5V
1R
(L/F) O Knock sensor OV or 2—7V While knocking:
Approx. 0.001
1S — — — — —
1T o Ignition switch
(ON position) Approx. 12V
1U — — — — —
1V — — — — —
1W o Test connector Test connector grounded: OV Test connector not grounded: approx. 12V Green connector, 1-pin
1X o Igniter Approx. 12V *Approx.1V 'Engine Signal
Monitor: green and
red lights flash
2A (U/F) o V ref 4.5—5.5V
2B o Air flow sensor
(Ground) OV
2C — — Ground (E2) OV
2D (U/F) o Oxygen sensor OV 0-1.0V
• Cold engine: 0V at idle
• After warming-up: Increase engine speed: 0.7—1.0V Deceleration: 0—0.2V
2E o Air flow sensor
(Intake air mass) 1.0—1.6V 1.7—2.3V Increase engine speed: voltage increases
2F — — — .— —
2G (U/F) o Throttle sensor Accelerator pedal released: approx. 0.5V
Max. voltage (Throt-tle valve fully opened): approx. ,4.3V
2H (L/F) o Air flow sensor (Variable resister) 0-5V Depends on
adjustment
21 o Water thermo sensor Approx. 0.4V
Engine coolant
temp. 20°C (68°F):
approx. 2.5
2J o Intake air thermo sensor (Dynamic chamber)
Approx. 2.5V at 20°C (68°F)
2K o
Solenoid valve (Pressure regula-tor control)
For 120 sec. after ignition switch OFF - ON: below 2.5V
For 120. sec after starting: below 2.5V
During hot condi-tion: Coolant temp, above 70°C (158°F) Intake air temp, above 30°C (86°F) ...Unleaded fuel above 50°C (122°F) ...Leaded fuel
2K o
Solenoid valve (Pressure regula-tor control)
ADDrox. 12V Other conditions
2L — — — — —
Note
a) Terminal labeled "U/F" are only for unleaded fuel.
b)Terminal labeled "L/F" are only for leaded fuel.
4C-100

CONTROL SYSTEM 4C
Terminal Input Output Connection to Voltage (After warming-up) Remark Terminal Input Output Connection to Ign: ON Idle Remark
2M
(U/F) o Oxygen sensor
heater Below 2.5V Above 3000 rpm: Approx. 12V
2N
(U/F) o Solenoid valve (EGR) Below 2.5V
• Radiator temp, below 17°C (62.6°F) or cool-ant temp, below 70°C (158°F): constant below 2.5 V
• 1,500-3,500 rpm: approx. 12V
20 (U/F) 0 Solenoid valve (No.2 purge control) Approx. 12V
• Coolant temp, below 75 °C (167°F): constant approx. 12V
• During medium and high load of above 1,700 rpm: below 2.5V
2P
(U/F) o
Solenoid valve
(No.1 purge
control)
Below 2.5V
Coolant temp, below 70°C (158°F): ap-prox. 12V
2Q o Solenoid valve (Idle speed control) Approx. 9—11V
2R — — Ground (E02) OV
3A — — Ground (E01) OV
3B O Ignition switch
(Start position) Below 2.5V While cranking: ap-
Drox. 10V
3C o Injector (No.2) Approx. 12V *1 Approx. 12V
*1 Engine Signal Monitor green and red liahts flash
3D — — — — —
3E o Injector (No.1) Approx. 12V *1 Approx. 12V
*1 Engine Signal
Monitor: gree and
red liahts flash
3F 0 Injector (No.4) Approx. 12V *1 Approx. 12V
*1 Engine Signal Monitor: gree and red liahts flash
3G — Ground (E1) OV
3H o Injector (No.3) Approx. 12V 'Approx. 12V *1 Engine Signal
Monitor: green and
red lights flash
31 0 — Control relav ADDrox. 12V
3J — — Battery Approx. 12V For back-uD
76G04C-179
Note
Terminals labeled "U/F" are only for unleaded fuel.
Terminal Location
31 3G 3E 3C 3A
3J 3H 3F 3D 3B
2Q 2d 2M *
L CM
2G 2E 2C <
CM

2R 2P 2N 2L 2J 2H 2F 20 2B
1W 1U 1S 1Q 10 1M 1K 11 1G 1E 1C 1A
1X 1V 1T 1R 1P 1N 1L 1J 1H 1F 1D 1B
4C-101

4C CONTROL SYSTEM
E/L CONTROL UNIT
Inspection
1. Connect a voltmeter between the E/L control unit
and a ground.
2. Start the engine and check the terminal voltages
as described below.
76G04C-180
Terminal Input Output Connection to Voltage (after warm-up) Remarks Terminal Input Output Connection to Ignition switch: ON Idle Remarks
A
(BW) — — Ignition switch Approx. 12V
B — — — — — —
C
(B) — — Ground OV
D (LY) O Electrical fan relay Approx. 12V Coolant temp.: below 97°C (207°F) D (LY) O Electrical fan relay
Below 1,5V Coolant temp.:
above 97°C (207°F)
E (GY) Control unit (11) OV E/L: ON E (GY) Control unit (11)
Approx. 12V E/L: OFF
F (W) O Headlight switch Approx. 12V Headlight switch:
ON F (W) O Headlight switch
Below 1,5V Headlight switch:
OFF
G (LB) o Blower motor switch Below 1.5V Blower motor switch: ON (3rd or 4th position) G (LB) o Blower motor switch
Approx. 5V Others
H
(BL) o Rear defroster
switch
Below 1.5 V Rear defroster
switch: ON H
(BL) o Rear defroster
switch Approx. 12V Rear defroster switch: OFF
76G04C-181
Replacement
1. Replace the E/L control unit.
2. Install in the reverse order of removal.
76G04C-182
4C—102

ON-VEHICLE MAINTENANCE 4D
INJECTION TIMING
1. Disconnect the negative battery cable.
2. Release the CSD using the screw driver.
3. Remove the cover on the clutch housing.
4. Turn the flywheel and set the indicator at TDC.
5. Disconnect the injection pipes from the injection
pump.
76G04D-008
6. Remove the hydraulic head plug from the injec-
tion pump.
7. Mount the SST into the plug hole on the hydraulic
head so the tip of the dial gauge pointer touches
the plunger end of the pump and the dial gauge
indicates approx. 2.0 mm (0.08 in).
76.G04D-009
8. Turn the crankshaft slowly counterclockwise to
30—50° BTDC.
9. Make sure the dial indicator pointer no longer
moves by slightly turning the crankshaft.
10. Set the dial gauge scale to Zero at the pointer.
76G04D-010
11. Turn the crankshaft clockwise to align the indica-
tor pin at ATDC 1° (RF-CX), TDC 0° (RF-N).
12. Read the dial gauge.
Cam lift: 0.98—1.02 mm (0.038—0.040 in)
13. If not within the specification, adjust the injection
timing. (Refer to page 4D—24.)
76G04D-011
4D-5

4D SUPERCHARGING SYSTEM (RF-CX)
INTERCOOLER
Removal and Installation
1. Remove in the sequence shown in the figure.
2. Install in the reverse order of removal.
3. Check for air leakage.
76G04D-037
5. Front bumper (Refer to Section 14.)
6. Cooling fan
7. Air pipe
8. Intercooler
Inspection
Check the intercooler for cracks or damage. Replace
if necessary.
8—11 N-m (80—110 cm-kg, 69—95 In-lb)
1. Battery
2. Battery carrier
3. Front grille (Refer to Section 14.)
4. Headlight (Refer to Section 14.)
76G04D-038
4D—16

DISTRIBUTOR 5
7BU05X-075
86U05X-048
76G05X-007
DISTRIBUTOR
SPARK TEST
1. Disconnect the distributor lead from the distributor.
2. Hold it with insulated pliers approx. 5—10 mm
(0.20—0.39 in) from a ground.
3. Crank the engine and check that a strong blue
spark is visible.
4. If there is no spark, the ignition coil or pick-up coil
may be bad.
Check once again after replacing the ignition coil
or pick-up coil.
IGNITION TIMING
1. Warm up the engine to the normal operating tem-
perature.
2. Turn all electric loads OFF.
3. Connect a tachometer and timing light to the
engine.
4. Connect a jumper wire between the test connec-
tor and ground. (Only for FE DOHC)
5. Check the idle speed. Set to the specified speed
if necessary.
Idle speed: 750 ± 50 rpm (FE DOHC)
800 t58 rpm (F6, F8 FE—MTX)
900 i58 rpm (F8, FE—ATX
in "P" range)
950 -5o rmp (F6—ATX
in "P" range)
6. Check that the timing mark (Yellow) on the crank-
shaft pulley and the mark on the timing belt cover
are aligned.
Ignition timing:
FE DOHC: 12 ± 1° BTDC
(Test connector grounded)
Others: 6 ± 1°
(Vacuum hoses disconnected and
plugged)
76G05X-008
5—11

DISTRIBUTOR
8.
If
the mark is not aligned, loosen the distributor lock
bolt, and turn the distributor housing to make the
adjustment.
9. Reconnect the vacuum hoses, or disconnect the
jumper wire from the test connector.
10. Tighten the distributor lock bolt to specified torque.
Tightening torque:
18.6—25.5 Nm
(1.9—2.6 m-kg, 13.7—18.8 ft-lb)
86U05X-051
SPARK CONTROL (Except FE DOHC)
Centrifugal Advance
1. Warm up the engine to the normal operating tem-
perature.
2. Check that the idle speed and initial ignition tim-
ing are correct.
3. Disconnect the vacuum hoses from the vacuum
control unit and plug them.
76G05X-009
F6
Engine Speed (rpm)
4. While gradually increasing the engine speed, use
a timing light to check the advance on the pulley.
Excess advance weak governor spring
(If the governor spring is broken,
the advance will rise very high)
Insufficient advance...governor weight or cam
malfunction
86U05X-053
F8
Engine Speed (rpm) Engine Speed (rpm)
5-12