1987 MAZDA 626 fuel

4A CONTROL SYSTEM
Idle switch
Adjust screw
76G04A-180
76G04A-181
5. Increase the engine speed to more than 2,000 rpm
and decelerate gradually.
6. Check the voltage.

Specification
Engine speed
^^^

FE 8Valve—
Unleaded Fuel
& F6 Sin-
gapore
Others
At idle below 1,5V Battery voltage
Above 1,000—1,100 rpm Battery voltage below 1.5V

7. If the voltage is not within specification, turn the ad-
just screw to adjust.
VACUUM SWITCH
On-Vehicle Inspection
1. Run the engine at idle.
2. Connect a voltmeter to the vacuum switch connec-
tor terminal wire (LB).
Voltage: Approx. 12V
3. Disconnect the vacuum hose from the vacuum
switch, and plug it.
4. Check the voltage.
Voltage: Less than 1.5V
Off-Vehicle Inspection
Inspection
1. Remove the vacuum switch.
2. Connect a vacuum pump to the vacuum switch.
3. Connect an ohmmeterto the vacuum switch, and
check the continuity between the switch terminals.

Vacuum Continuity
MTX: More than 300 mmHg (11.8 inHg) No ATX: More than 200 mmHg (7.9 inHg) No
Others Yes

76G04A-182
4A—94

4A EXHAUST SYSTEM
EXHAUST SYSTEM
EXCEPT FE 8VALVE—UNLEADED FUEL
Removal and Installation
1. Remove in the sequence shown in the figure.
2. Install in the reverse order of removal.
Torque specifications
1. Center silencer and main silencer
2. Brackets
76G04A-187
3. Front silencers
4. Exhaust manifolds
Inspection
Visually check the exhaust system for cracks or
damage.
4A—96

EXHAUST SYSTEM 4A
FE 8 VALVE-UNLEADED FUEL
Removal and Inspection
1. Remove in the sequence shown in the figure
2. Install in the reverse order of removal.
Torque Specifications

L

22—28 N-m (2.2—2.9 m-kg, 16—21 ft-lb)
34—49 N-m (3.5—5.0 m-kg, 26—36 ft-lb)
55—60 N-m (5.6—8.2 m-kg, 40—59 ft-lb)
.8—11 Nm .8—1.1 m-kg, 69—95 in-lb)
N-m 3 m-kg, 25—38 ft-lb)
76G04A-189
1. Main silencer
2. Middle pipe
3. Pre-silencer
4. Catalytic converter
5. Bracket
6. Front pipe
Inspection
1. Check the catalytic converter and exhaust pipe for
deterioration or restriction.
2. Check the insulation covers welded onto the cata-
lytic converter for damage.
Note
If the insulation cover is touching the catalytic
converter housing, excessive heat at the floor
will occur.
76G04A-190
4A-97

FUEL AND EMISSION
CONTROL SYSTEMS
(FUEL INJECTION FE)
OUTLINE 4B— 2
SYSTEM DIAGRAM 4B— 2
COMPONENT LOCATION 4B— 3
VACUUM HOSE ROUTING
DIAGRAM 4B— 5
SPECIFICATIONS 4B— 6
TROUBLESHOOTING GUIDE 4B— 7
TROUBLESHOOTING
PROCEDURE 4B— 7
TROUBLESHOOTING WITH SST.... 4B— 9
INSPECTION PROCEDURE 4B—10
AFTER-REPAIR PROCEDURE 4B—10
PRINCIPLE OF CODE CYCLE 4B—12
CODE NUMBER 4B—13
SWITCH MONITOR FUNCTION 4B—25
INSPECTION PROCEDURE 4B—26
IDLE SPEED 4B—29
IDLE MIXTURE 4B—29
INTAKE AIR SYSTEM 4B—30
COMPONENT DESCRIPTIONS 4B—30
REMOVAL 4B—31
PARTS INSPECTION 4B—32
INSTALLATION 4B—34
IDLE-UP SYSTEM 4B—35
COMPONENT DESCRIPTIONS 4B—36
TROUBLESHOOTING 4B—37
AIR VALVE 4B—38
AIR BYPASS SOLENOID VALVE ... 4B—39
FUEL SYSTEM 4B—42
COMPONENT DESCRIPTIONS 4B—43
TROUBLESHOOTING 4B—44
FUEL PRESSURE RELEASE AND
SERVICING FUEL SYSTEM 4B—45
MULTI-PRESSURE TESTER 4B—46
FUEL PRESSURE 4B—48
FUEL PUMP 4B—49
PULSATION DAMPER 4B—50
INJECTOR 4B—51
PRESSURE REGULATOR
CONTROL SYSTEM 4B—53
COMPONENT DESCRIPTIONS 4B—54
TROUBLESHOOTING 4B—55
REPLACEMENT 4B—57
FUEL TANK 4B—61
DECELERATION CONTROL
SYSTEM 4B—64
COMPONENT DESCRIPTIONS 4B—65
TROUBLESHOOTING 4B—66
AIR INJECTION SYSTEM 4B—68
COMPONENT DESCRIPTIONS 4B—68
TROUBLESHOOTING 4B—69
EXHAUST GAS RECIRCULATION
(EGR) SYSTEM 4B—71
COMPONENT DESCRIPTIONS 4B—71
TROUBLESHOOTING 4B—72
EVAPORATIVE EMISSION
CONTROL (EEC) SYSTEM 4B—74
COMPONENT DESCRIPTIONS 4B—74
TROUBLESHOOTING 4B—75
POSITIVE CRANKCASE
VENTILATION (PCV) SYSTEM 4B—80
COMPONENT DESCRIPTION 4B—80
EXHAUST SYSTEM 4B—81
REMOVAL AND INSTALLATION ... 4B—82
INSPECTION 4B—82
CONTROL SYSTEM 4B—83
RELATIONSHIP CHART 4B—84
EGI MAIN FUSE 4B—86
MAIN RELAY 4B—86
CIRCUIT OPENING RELAY 4B—86
ENGINE CONTROL UNIT 4B—87
NEUTRAL SWITCH 4B—91
CLUTCH SWITCH 4B—91
BRAKE LIGHT SWITCH 4B—91
P/S PRESSURE SWITCH 4B—92
INHIBITOR SWITCH 4B—92
E/L CONTROL UNIT 4B—93
AIR FLOW METER 4B—94
THROTTLE SENSOR 4B—95
WATER THERMO SENSOR 4B—97
WATER THERMO SWITCH 4B—97
OXYGEN SENSOR 4B—98
ATMOSPHERIC PRESSUFfE
SENSOR 4B—99
76G04B-001

4B OUTLINE
SPECIFICATIONS
Item Specification

Idle speed rpm MTX: 800 +5„° (Neutral), ATX: 900 +5S
(P
range)

Throttle body

Type Horizontal draft (1 -barrel)
Throat diameter mm (in) 50 (2.0)

Air flow meter

E2-VS More than
20

E2-VC 100-300
Resistor
Q
E2-VB 200—400 Resistor
Q

E2-THA -20°C
(
—4°F) 13,600-18,400 20°C
(
68°F) 2,210-2,690 60°C (140°F)
493- 667
Air cleaner

Element type Oil permeated

Fuel pump

Type Impeller
(in
tank)
Output pressure kPa (kg/cm2,
psi)
441-588 (4.5-6.0, 64—85)
Feeding capacity cc (cu in)/10 sec. 220 (13.4) minmum

Fuel filter

Type Low pressure side Nylon element Type High pressure side Paper element

Pressure regulator

Type Diaphragm
Regulating pressure kPa (kg/cm2,
psi)
235-275 (2.4—2.8, 34—40)

Injector
TvDe
Hiqh-ohmic
Type
of
drive Voltage
Resistance
fi
12-16
Injection amount cc (cu
in) 15
seconds 38—53 (2.3-3.2)

Fuel tank

Capacity liters (US gal, Imp gal) 60 (15.9, 13.2)

Fuel

Soecification Unleaded reaular

76G04B-506
4B—6

TROUBLESHOOTING GUIDE 4B
TROUBLESHOOTING GUIDE
This troubleshooting guide shows the malfunction numbers and the symptoms of various failures.
Perform troubleshooting as described below.
Possible cause
Symptom
Input sensors and switches
o> Q.
C
0
Jh c 01
4B-14
a> 4)
E
o
4B-1S
o in c « m o E k_ 0) c.
0 <0 £
4B-16
o CO c a> 0) o E
a>
.x
co
4B-17
o 10 c a) co
4B-18
o in c a> (0
o> o> a>
a) £ a VI o E
4B-19
0 <0 c a> 0) c a> 01
S? o
4B-20
E a> in (0
o 10 A •o 0) 0> u.
4B-21
Output solenoid valves
o «
3 O) 0)
0) 0) 01
0> > 10 >
•o o c V o tt)
4B-22
0)
OI

0> > CO >

TJ
O c 0> o CO
4B-23
oc O u
o> > 75 >
•o o c a> o 05
4B-23
0 a. 3 1
2
0) > (0 >
"D O
o 0> in in a a >. £
4B-23
ffl a 3 • a>
2
a> > 10 >
"O o c a> o
CO Q. >. JO
4B-24
Fault Indicated by SST
Code No. 01 08 09 10 12 14 15 17 25 26 28 34 35
Hard start or won't start
(Cranks OK)
Engine stalls
Rough
idle
While warming up
After warming up
While warming up
After warming up
High idle speed after
warming up
TROUBLESHOOTING PROCEDURE
Note
Step 1 under symptom is to quickly determine what system or unit may be at fault by use of the SST. (Self-Diagnosis Checker 49 H018 9A1)
1st:
Check input sensors and output solenoid valves with the
SST.
(Refer
to
page 4B—10.)

2nd:
Check other switches with the
SST.
(Refer
to
page 4B—26.)

3rd:
Check the following items:

11
Poor acceleration, hesita-
tion or lack of power
Runs rough on deceleration
Afterburn in exhaust system
Poor fuel consumption
Engine stalls or rough after hot starting
Electrical system
1) Battery condition
2) Fuses

Fuel system
1) Fuel level 2) Fuel leakage
3) Fuel filter 4) Idle speed

Engine
1) Compression 2) Overheating

Ignition system

1) Ignition spark 2) Ignition timing

Intake air system
1)
Air
cleaner element 2) Vacuum
or air
leakage 3) Vacuum hose routing
4) Accelerator cable

Others
1) Clutch slippage 2) Brake dragging

Fails emission test 4th:
Check Fuel and Emission Control Systems. (Refer
to
page 4B—8.)

76G04B-003
4B—7

4B TROUBLESHOOTING GUIDE
The Troubleshooting Guide lists the systems most likely
to
cause
a
given symptom. After finding
sys-

tems
to
check, refer
to
the
pages shown
for
detailed guides
for
each system.

Possible
cause

Fuel
and
Emission Control Systems

Possible
cause
Intake
Air
System
(Poor
connection
of
components,
throttle
body)

Fuel

System
(Fuel

injection,

Fuel
pressure)
Pressure
Regulator
Control
System
Idle-up
System

(Air

valve,
solenoid
valve
malfunction)

EGR

System

(EGR

control
valve
stuck
and
open)

EEC

system
(Vacuum
switch
valve,
No.1
purge
control
valve
malfunction)
PCV

System
(System

clogged)

Deceleration

System
(Dashpot,
fuel
cut
operation
malfunction)

Air

injection

system
(Reed
valve
malfunction)
Exhaust
system

(System

clogged)

Page 4B—30 4B—42 4B—53 4B—35 4B—71 4B—74 4B—80 4B—64 4B—68 4B—81

Symptom

2
2 1

Symptom

3

4 3 1 2

Symptom

3
5 4 2 3 1

Symptom

4
6 5 1 4 2 3

Symptom

4
7 6 2 4 5 1 3

Symptom

5
3 1 2

Symptom
6
3 4 1 2 5
Symptom

7
3 2 1

Symptom

8
3 4 1 2

Symptom

9
2 3 1 4

Symptom

10
2 1

Symptom

11
7 8 5 2 6 3 4 1

76G04B-004
The numbers
of
the list show the priorities
of
inspections from the most possible to that with
the
lowest
possibility.
These were determined
on the
following basis:
• Ease
of
inspection
•
Most possible system
•
Most possible point
in
system
4B—8

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