1987 MAZDA 626 engine

IDLE-UP CONTROL SYSTEM 4 A
FE (Middle East) and F6 (General)
Possible cause
jrvo

diaphragm

3
jrvo

diaphragm

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Page 4A—72 4A—74 4A—74 Section 15 4A—75 Section 16
Checking order 1 2 3 4 5 6 7 8
76G04A-136
FE 8Valve—Unleaded Fuel
Posible cause

Engine

control

unit

terminal

Servo

diaphragm

Vacuum

signal

Solenoid

valve £ O **
S CO O
£ U
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(for
A/C) ** n ** w o E «
Refrigerant
pressure

switch
H D I Servo

diaphragm

Vacuum

signal

Solenoid

valve
< a. Relay
(for
A/C)
H Refrigerant
pressure

switch

Page 4A—91 4A—72 4A—74 4A—74 Section 15 4A—75 Section 16
Checking order 9 1 2 3 4 5 6 7 8
76G04A-137
4A—71

4A IDLE-UP CONTROL SYSTEM
Servo Diaphragm
Dual servo diaphragm type
1. Warm up the engine and run it at idle.
2. Connect a tachometer to the engine.
3. Disconnect the vacuum hose from the servo di-
aphragm port A.
4. Apply intake manifold vacuum directly to the di-
aphragm.
Caution
All accessories must be OFF.
76G04A-138
5. Check that the engine speed is within the specifi-
cation.
Engine speed: 1,200—1,400 rpm
6. If not within specification, turn the adjust screw to
adjust.
7. Reconnect the vacuum hoses.
76G04A-139
8. Disconnect the solenoid valve vacuum hose from
the servo diaphragm port B.
9. Apply intake manifold vacuum directly to the di-
aphragm.
10. Check that the engine speed is within specification.
Engine speed: 800—1,000 rpm (MTX)
1,050—1,250 rpm (ATX)
(in N range)
76G04A-140
Adjust screw
11. If not within specification, turn the adjust screw to
adjust.
12. Reconnect the vacuum hoses.
76G04A-141
4A—72

IDLE-UP CONTROL SYSTEM 4A
Single servo diaphragm type
1. Warm up the engine and run it at idle.
2. Connect a tachometer to the engine.
3. Disconnect the vacuum hose from the servo di-
aphragm.
4. Check that the engine speed is within specification.
Engine speed:
P/S operated 800—1,000 rpm (MTX) P/S operated 1,050—1,250 rpm (ATX) (in N range)
A/C operated 1,200—1,400 rpm
76G04A-142
6. If not within specification, turn the adjust screw to
adjust.
76G04A-143
4A-73

4A IDLE-UP CONTROL SYSTEM
76G04A-144
76G04A-145
76G04A-146
Vacuum Signal [Equipped with A/C, only FE and
F8 (Except Middle East and General)]
1. Start the engine and run it at idle.
2. Disconnect the vacuum hose from the servo di-
aphragm.
3. Place a finger over the hose.
4. Increase the engine speed, and check for vacuum.
Engine model Engine speed Vacuum
pj| (Except Middle) Below 2,300 rpm Yes pj| (Except Middle) Above 2,300 rpm No
FE (Unleaded fuel) Below 1,500 rpm Yes FE (Unleaded fuel) Above 1,500 rpm No
F6 (Singapore) Below 2,100 rpm Yes F6 (Singapore) Above 2,100 rpm No
General and Middle East
1. Start the engine and run it at idle.
2. Disconnect the vacuum hose from the servo di-
aphragm.
3. Place a finger over the hose.
4. Operate the A/C or P/S.
5. Check that vacuum is felt.
P/S Switch
1. Start the engine and run it at idle.
2. Disconnect the power steering switch connector.
3. Connect an ohmmeter to the power steering
switch.
4. Turn the steering wheel all the way to either the
right or left, and check for continuity.
P/S Continuity
Operated Yes
Not operated No
5. Replace if necessary.
Solenoid Valve (A/C)
1. Disconnect vacuum hose A from the servo di-
aphragm.
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.
76G04A-147
4A-74

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
\ Page
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Engine

i
terminal
E a>
s. CO
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

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