1987 MAZDA 626 steering

ISC SYSTEM 4C
COMPONENT DESCRIPTION
Component Function Remark
A/C switch Detects air conditioner operation; sends
signal to engine control unit Switch ON when air conditioner
operating
Air valve When cold, supplies bypass air into dy-namic chamber • Engine speed increased to shorten warm-up period • Thermo wax type
• Installed in BAC valve
Clutch switch Detects in-gear condition; sends signal to engine control unit Switch ON when clutch pedal released
E/L control unit Detects that E/L is being applied; sends
signal to engine control unit
Engine control unit Detects signals from input sensors and switches; controls solenoid valve (Idle speed control)
Idle switch Detects when throttle valve fully closed;
sends signal to engine control unit
Installed on throttle body
Ne signal pick-up Detects crank angle at 180° intervals; sends signal to engine control unit Installed in distributor
Neutral switch Detects in-gear condition; sends signal to engine control unit
Switch ON when in gear
P/S pressure switch Detects P/S operation; sends signal to engine control unit Switch ON when steering wheel turned right or left
Solenoid valve (Idle speed control) Controls bypass air amount • Controlled by duty signal from engine control unit • Installed in BAC valve
• Operates idle-up
Test connector For initial idle speed adjustment • Gerrn, 1-pin
• Idle speed feedback control cancelled when connector grounded
Water thermo sensor Detects coolant temperature; sends
signal to engine control unit
76G04C-078
4C—45

ISC SYSTEM 4C
76G04C-081
76G04C-082
Cooling fan switch
Rear defroster switch
Head light switch
Blower motor switch
ISC "valve
76G04C-083
(ISC valve)
6. Connect the ISC valve connector.
Note
a) Make sure that the initial idle speed is set
to specification.
b) All accessory must be OFF.
7. Again disconnect the ISC valve connector (engine
at normal operating temperature).
8. Check that the engine speed decreases.
9. Reconnect the ISC valve connector.
10 Remove the jumper wire from the test connector
and make sure that the idle speed is within specifi-
cations.
(Load Test)
11. Apply power steering, electrical, and air conditioner
loads and check that the idle speed is controlled
to within specifications.
Load Idle speed
P/S 750 ± 50
E/L 800 ± 50
A/C 800 ± 50
E/L and A/C 800 ± 50
BAC Valve
Air valve
1. Remove the BAC valve from the throttle body.
2. Blow air through the valve from port A and check
that air comes out of port B when the BAC valve
is cold..
3. If not correct, replace the BAC valve.
Note
Refer to "Installation" on this page for the
BAC valve installation.
86U04A-063
4C—47

FUEL SYSTEM 4C
FUEL SYSTEM
76G04C-087
This system supplies the necessary fuel for combustion at a constant pressure to the injectors. Fuel
is metered and injected into the intake manifold according to the injection control signals from the en-
gine control unit. It consists of the fuel pump, fuel filters, delivery pipe, pulsation damper, pressure
regulator, injectors, fuel pump control unit, and the control relay.
The fuel pump is mounted in the fuel tank to minimize the operating noise of the fuel pump. The injec-
tors directly supplied with battery voltage through the control relay. The connector of the injectors is
white to distinguish the injectors for FE DOHC from those of other engines.
Due to the installation of the steering angle transfer shaft for the 4-wheel steering (4WS) the fuel tank
of 4WS vehicles is designed with separate right and left sections. A transfer pump is used to pump
fuel from the left side to the right side.
4C—49

FUEL SYSTEM 4C
5. Connect the SST to the battery and injector.
6. Check the injection volume with a graduated con-
tainer.
Injection volume:
Approx. 66—91 cc (4.03—5.55 cu in) /15 sec.
Caution
When using the SST, make sure of the SST
number and use correct one.
7. If not correct, replace the injector.
76G04C-107
Rear seat Cushion Release Button -
76G04C-108
TRANSFER PUMP CONTROL SYSTEM (4 WHEEL
STEERING)
1. Remove the rear seat. (Refer to 14 section.)
2. Remove the fuel filler cap.
3. Turn the ignition switch ON.
Note
a) The tank should be more than 1/3 full.
b) Due to the delay timer, transfer pump oper-
ation begins approx. 10 sec. after the igni-
tion switch is turned ON.
4. Listen for the operational sound of the transfer
pump.
5. Install the fuel filler cap.
6. If no sound was heard, check the voltage at the
transfer pump connector.
Terminal (wire) Voltage
A, C (WG) Approx. 12V
I, J (B) OV
86U04B-075
I C A
lb d
cp a • • •
J
76G04C-211
7. If the voltages are correct, replace the transfer
pump.
8. If not correct, disconnect the transfer pump con-
nector.
9. Check the voltage at the terminals below.
Terminal (wire) Voltage
A, C (WG) Approx. 12V
I, J (B) OV
10. If the voltages are correct, replace the transfer
pump.
4C—59

FUEL SYSTEM 4C
FUEL TANK
Removal
Caution
a) Before performing the following procedure, release the fuel pressure from the fuel sys-
tem to reduce the possibility of injury or fire. (Refer to page 4C—52.)
b)When removing the fuel tank, keep sparks, cigarettes, and open flames away from the
fuel tank.
Remove in the sequence shown in the figure.
76G04C-125
Note
Drain the fuel from the fuel tank before removing the tank.
1. Remove fuel filler cap.
2. Fuel pump connectors
3. Fuel hoses
4. Steering angle transfer shaft (4-wheel
steering)
(Refer to section 10)
5. Cross member (4-wheel steering)
6. Evaporative hoses
7. Fuel filler hose
8. Breather hose
9. Parking cable bracket
10. Fuel tank strap
11. Fuel tank
4C-65

FUEL SYSTEM 4C
Installation note
Hoses
1. Push the ends of the main fuel hose, fuel return
hose, and evaporation hoses onto the fuel tank fit-
tings at least 25 mm (1.0 in).
2. Push the fuel filler hose onto the fuel tank pipe and
filler pipe at least 35 mm (1.4 in).
Steering angle transfer shaft
(4-wheel steering)
Refer to section 10
4C—67

CONTROL SYSTEM 4C
Resistance
Check resistance between the terminals with an
ohmmeter.
Between terminals Resistance (Q)
1B « 1D More than approx. 20
2F <- 1C More than approx. 60
2F « 1A oo
2B « 2D More than approx. 60
2B ~ 2C oo
NEUTRAL SWITCH
Inspection
1. Disconnect the neutral switch connector.
2. Connect an ohmmeter to the switch.
3. Check continuity of the switch.
Transmission Continuity
In neutral No
In other ranges Yes
4. Reconnect the switch connector.
Note
Refer to Section 7A for replacement of the
neutral switch.
CLUTCH SWITCH
Inspection
1. Disconnect the clutch switch connector.
2. Connect an ohmmeter to the switch.
3. Check continuity of the switch.
Pedal Continuity
Depressed No
Released Yes
4. Reconnect the switch connector.
Note
Refer to Section 6 for replacement of the
clutch switch.
P/S PRESSURE SWITCH
Inspection
1. Disconnect the P/S pressure switch connector.
2. Connect an ohmmeter to the switch.
3. Start the engine. Check continuity of the switch
while turning the steering wheel at idle.
P/S Continuity
Turning Yes
Not turning No
4. Reconnect the switch connector.
Note
Refer to Section 10 for replacement of the P/S
pressure switch.
4C-97

REMOVAL 7A
RF-N and RF-CX
1. Battery
2. Air cleaner assembly
3. Vacuum hose
4. Intercooler pipe and hose
(RF-CX)
5. Electric fan
6. Speedometer cable
7. Ground(s)
8. Clutch release cylinder
9. Pressure and return hoses
(power steering)
10. Starter
11. Wheel
12. Splash shield
13. Stabilizer
14. Joint shaft
15. Extension bar
16. Control rod
76G07A-011
17. Exhaust pipe bracket
18. Water pipe
19. Gusset plate (rear)
20. Gusset plate (front)
21. Under cover
22. Engine mount No.4
23. Engine mount No.2
24. Crossmember
7 A—13