1987 MAZDA 626 Workshop Manual

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

IDLE-UP CONTROL SYSTEM 4A
Troubleshooting
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting. (Refer to page 4A—70.)
\\ Possible cause
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Symptom
Section
15 Section 15 4A—95 4A—93 Section
15 4A—77 4A—86— 4A—91 4A—77
Checking order 3 4 5 6 7 8 2 9 1
76G04A-152
'Engine control unit terminal Check the following terminal voltages
Transmission Terminal
MTX A, C, D, H, Q, R
ATX I, 2B, 2C, 2D, 2E, 2H, 2M
System Inspection
1. Warm up the engine and run it at idle.
2. Connect a jumper wire to the carburetor connec-
tor terminal wire (YW) and ground.
3. Connect a tachometer to the engine.
4. Turn all accessories off.
5. Verify that the engine speed is within specification.
Engine speed: 900—950 rpm (MTX)
Engine speed: 1,000—1,050 rpm
(ATX; in N range)
6. Disconnect the tachometer.
76G04A-153
Idle-up Solenoid Valve
1. Turn all accessories OFF and turn the ignition
switch ON.
2. Disconnect the idle-up solenoid valve connector.
3. Ground the carburetor connector terminal wire
(YW) using with a jumper wire.
4. Check the rod is drawn into the valve.
5. Replace if necessary.
U
76G04A-154
4A-77

4 A EVAPOTATIVE EMISSION CONTROL SYSTEM
EVAPORATIVE EMISSION CONTROL SYSTEM
(MIDDLE EAST)
76G04A-155
Operation
Cold engine — below 50°C (122°F)
The No. 1 purge control valve does not operate because the vacuum passage of the water thermo
valve is opened to the atmospheric air side.
Warm engine — above 50 °C (122°F)
1. During normal driving, the carburetor vacuum signal is led to the No. 1 purge control valve with
the result that fuel vapors are drawn into the intake manifold.
4A—78

EVAPORATIVE EMISSION CONTROL SYSTEM 4A
Troubleshooting
Possible cause No. 1 purge No. 2 purge Water thermo Three-way control valve control valve valve check valve
Page 4A—79 4A—79 4A—79 4A—37
Checking order 1 2 3 4
76G04A-156
No. 1 Purge Control Valve
1. Blow through the purge control valve from port A
and check that air does not flow.
2. Connect a vacuum pump to the purge control
valve.
3. Apply 110 mmHg (4.29 inHg) vacuum with a
vacuum pump, and blow through port A again; air
should flow.
76G04A-157
No. 2 Purge Control Valve
1. Disconnect vacuum hose A from the pipe.
2. Check the air flow of the No. 2 purge control valve.
Specification:
15—35 mmHg (0.6—1.4 inHg): Below
-8—18 mmHg (0.3—0.7 inHg): Suck
76G04A-158
(B)"
* = zu
Blow
'(A)
/ (ft
Water Thermo Valve
1. Remove the water thermo valve.
2. Place the valve in water with a thermometer.
3. Heat the water gradually to 50°C (122°F).
4. Blow through the valve from hose A and check that
air comes out of port B.
76G04A-159
4A-79

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

IGNITION TIMING CONTROL SYSTEM 4A
TROUBLESHOOTING
Check the condition of the wiring harness and components before checking the sensors or switches.
\\ Possible cause , . Engine control unit terminal
\ Page

rater

thermo

switch

itake

manifold)

'ater

thermo

switch

Iadiator)
hibitor

switch

Solenoid

valve

(Ignition

timing

contra

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5 >> n
acuum

control

unit

Ustributor)
Symptom \J

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o 5 t c
Solenoid

valve

(Ignition

timing

contra

O > B 1F 2A 2F 2H 2M Symptom \J 4A—95 4A—95 4A—93 4A—81 4A—82 Section 5 4A—85 4A--86
Poor accelera-
tion, hesitation, 5 6 4 2 3 1 11 7 8 9 10 or lack of power
Fails emission test 4 5 3 2 — 1 10 6 7 8 9
76G04A-161
Solenoid Valve (Ignition Timing Control)
1. Disconnect the vacuum hose from the solenoid
valve and vacuum pipe.
2. Blow through the solenoid valve from vacuum hose
A.
3. Check that air flows from port B.
76G04A-162
4. Disconnect the solenoid valve connector.
5. Connect 12V and a ground to the terminals of the
solenoid valve.
6. Blow through the solenoid valve from vacuum hose
A.
7. Check that air flows from the valve air filter.
76G04A-163
4 A—81

4 A IGNITION TIMING CONTROL SYSTEM
Delay Valve
1. Remove the delay valve.
2. Connect a vacuum pump to the valve as shown
in the figure.
3. Apply vacuum and check that it is released
gradually.
4. If not correct, replace the delay valve.
76G04A-164
5. Connect a vacuum pump to the valve as shown
in the figure.
6. Apply vacuum and check that it is not held.
7. If not correct, replace the delay valve.
76G04A-165
4A—82

CONTROL SYSTEM 4 A
CONTROL SYSTEM
Idle switch A/C switch
Water thermo switch
'Vacuum switch
Engine control switch
£
-Ignition coil
V
Water thermo switch
•Inhibitor switch
76G04A-166
The control system consists of the engine control unit, water thermo switches, A/C switch, P/S switch,
inhibitor switch, vacuum switch, and idle switch.
4A—83