1987 MAZDA 626 Workshop Manual

SWITCH MONITOR FUNCTION 4B
Idle switch
76G04B-026
Brake light switch
76G04B-027
Blower switch
76G04B-028
A/C switch
76G04B-029
4B—27

4B SWITCH MONITOR FUNCTION
Headlight switch
76G04B-030
Rear defroster switch
76G04B-031
Inhibitor switch
76G04B-032
Water thermo switch circuit (not included in switch inspection)
Warning
4B—28

IDLE ADJUSTMENT 4B
76G04B-034
76G04B-035
Idle mixture
Automatic
Control
Function
Engine Control Unit

IDLE
ADJUSTMENT
IDLE SPEED
Preparation
1) Check the condition of the engine (plugs, leaks in
hoses, etc.).
2) Make sure all accessories are OFF.
3) Warm up the engine and run it for three minutes
at 2,500—3,000 rpm in neutral.
4) Check the initial ignition timing and adjust if
necessary.
Inspection and Adjustment
Caution
Disconnect the air bypass solenoid connec-
tor when checking and adjusting the idle
speed.
1. Check that the idle speed is within specification.
Specification:
MTX—800 +58 rpm
ATX—900 +58 rpm (P range)
2. If the idle speed is not within specification, remove
the blind cap from the throttle body and adjust it
by turning the air adjust screw.
IDLE MIXTURE
Because an automatic compensation function
for air/fuel mixture is built into the engine con-
trol unit, it is not necessary to check and adjust
the idle mixture.
86U04A-049
4B-29

4B INTAKE AIR SYSTEM
INTAKE AIR SYSTEM
76G04B-036
This system controls the air required by the engine for operation. The system consists of the air duct,
air cleaner, air flow meter, throttle body, dynamic chamber, and intake manifold.
COMPONENT DESCRIPTIONS
Component Function Remarks
Air cleaner
Filters
air
into throttle body

Air flow meter
Detects amount
of
intake air;
sends signal
to
engine control unit Intake
air
thermo sensor and fuel pump
switch are integrated

Throttle body
Controls intake
air
quantity Integrated throttle sensor and idle switch

76G04B-037
4B—30

INTAKE AIR SYSTEM 4B
REMOVAL
Caution
Before removing the following parts, release the fuel pressure from fuel system to reduce
the possibility of injury or fire. (Refer to page 4B—45.)
Remove in the sequence shown in the figure.
1. Air flow meter connector
and secondary air hose
2. Air cleaner
3. Air duct
4. Resonance chamber
5. Air flow meter
6. Air hose
7. Vacuum hoses, air hoses,
and water hoses
8. Accelerator cable
9. Throttle sensor connector
10. Throttle body
11. EGR modulator valve
12. Air hose
13. Air bypass solenoid valve
76G04B-038
14. Intake manifold bracket
15. Dynamic chamber bracket
16. Fuel return pipe
17. Dynamic chamber
18. Injector connector
19. Delivery pipe assembly
20. Air valve
21. Intake manifold and gaskets
4B—31

4B INTAKE AIR SYSTEM
69G04A-059
86U04A-053
79G04D-084
PARTS INSPECTION
Air Cleaner Element
1. Check the condition of the air cleaner element.
2. Replace, if necessary.
Caution
Do not use the compressed air to clean the
air cleaner element.
Accelerator Cable
1. Inspect the deflection of the cable. If the deflec-
tion is not within 1—3 mm (0.04—0.12 in.), ad-
just by turning nuts A.
2. Depress the accelerator pedal to the floor and con-
firm that the throttle valve is fully opened. Adjust
by turning bolt B if necessary.
Throttle Body
Caution
a) The throttle adjust screw is preset and
sealed.
Do not attempt to adjust it.
If there is a malfunction of the throttle ad-
just screw, lever, or throttle valve, replace
the throttle body as an assembly.
b) Do not remove the thin sealing coating from
the throttle valve or bore.
79G04D-085
4B-32

INTAKE AIR SYSTEM 4B
76G04B-039
D C B E\\ I I A
p 'V > "
F G
76G04B-040
76G04B-041
1. Check that the throttle valve moves smoothly when
the throttle lever is moved from fully closed to fully
open.
2. Warm up the engine and run at idle.
3. Check the vacuum generated at each port as
shown in the following table.

~ —Condition
Port (Connected to) ——____ Idle Other
A (solenoid valve, EGR) No Yes
B (distributor, advance) No Yes
C (EGR modulator valve) No Yes
D (water thermo valve) No Yes
E (vacuum switch valve
&
charcoal canister) Yes
F (distributor, retard
& air
control valve) Yes
G (distributor, advance) Yes

4. If vacuum is not obtained as in the table, clean the
necessary port.
Dynamic Chamber
1. Visually check the dynamic chamber for damage.
2. Replace, if necessary.
Intake Manifold
1. Visually check the intake manifold for damage.
2. Replace, if necessary.
76G04B-042
4B—33

4B INTAKE AIR SYSTEM
INSTALLATION
install in the reverse order of removal.
Torque Specification
8—11 N-m (0.8—1.1 m-kg, 5.8—8.0 ft-lb)
19—25 N m (1.9—2.6 m-kg, 14—19 ft-lb)
19—25 N m (1.9—2.6 m-kg, 14—19 ft-lb)
8—11 Nm (0.8—1.1 m-kg, 5.8—8.0 ft-lb)
8—11 N-m (0.8—1.1 m-kg, 5.8—8.0 tt-lb)
a® ^£-5—7 N-m ;'(0.5—0.7 m-kg, 13.6—5.1 ft-lb)
8—11 Nm (0.8—1.1 m-kg 5.6—8.0 ft-lb)
19—25 N-m '41.9—2.6 m-kg, tf>14—19 ft-lb)
8—11 N-m (0.8—1.1 m-kg, 5.8—8.0 ft-lb)
8—11 N-m (0.8—1.1 m-kg 5.8—8.0 ft-lb)
4B—34
76G04B-125