1987 MAZDA 626 air filter

FUEL SYSTEM 4A
SEPARATOR
Inspection
Visually check the separator for fuel leakage and dam-
age. Replace, if necessary.
76G04A-055
TWO-WAY CHECK VALVE
(Except Middle East)
Inspection
1. Disconnect the hoses, and remove the check
valve.
2. Check that air flows in both directions through the
valve.
3. If not as specified, replace the two-way check
valve.
76G04A-056
THREE-WAY CHECK VALVE
(Middle East)
1. Blow through the valve from port and check
that air comes out of port (§).
Next, block port ©and check that air comes of
port ©.
2. Block port ©and apply vacuum with a vacuum
pump through port
3. Check that no vacuum is held.
76G04A-057
FUEL FILTER
Replacement
The fuel filter is mounted on the left side of the frame.
Caution
a) To prevent gasoline from draining during
removal, first disconnect and plug the in-
let hose.
b) During installation be sure to install the fuel
filter in the correct direction of flow.
76G04A-058
4 A—37

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

0) >
5 >> n
acuum

control

unit

Ustributor)
Symptom \J

•S-
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

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 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

4B FUEL SYSTEM
FUEL SYSTEM
76G04B-057
This system supplies the fuel necessary 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 switch (incorporated in the air flow meter), and the circuit opening relay.
The fuel pump is mounted in the fuel tank to minimize the operating noise of the fuel pump. The injec-
tors are directly supplied with battery voltage through the main relay.
4B—42

FUEL SYSTEM 4B
COMPONENT DESCRIPTIONS
Component Function Remarks
Air flow meter
Detects amount
of
intake
air;

sends signal
to
engine control unit Intake
air
thermo sensor and fuel pump
switch
are
integrated

Atmospheric pressure sensor
Detects atmospheric pressure; sends sig-nal
to
engine control unit

Circuit opening relay
Voltage
for
fuel pump while engine running

Clutch switch
Detects in-gear condition; sends signal
to
engine control unit Switch
ON
when clutch pedal released

Engine control unit
Detects signals from input sensors and switches; controls injector operation

Fuel filter
Filters particles from fuel

Fuel pump
Provides fuel
to
injectors • Operates while engine running
• Installed
in
fuel tank

Idle switch
Detects when throttle valve fully closed;
sends signal
to
engine control unit
Installed
in
throttle sensor

Ignition coil (-) terminal
Detects engine speed; sends signal
to
engine control unit

Ignition switch (ST position)
Sends engine cranking signal
to
engine control unit

Inhibitor switch
Detects in-gear condition; sends signal
to
engine control unit
Switch
ON in "N" or "P"
range

Injector
Injects fuel into intake port • Controlled
by
signals from engine control unit • High-ohmic injector

Intake air thermo sensor
Detects intake
air
temperature;
sends signal
to
engine control unit Installed
in air
flow meter

Main relay
Supplies electric current
to
injectors and engine control unit

Neutral switch
Detects in-gear condition; sends signal
to
engine control unit
Switch
ON
in-gear

Oxygen sensor
Detects Oxygen concentration; sends sig-nal
to
engine control unit
Zirconia ceramic and platinum coating

Pressure regulator
Adjusts fuel pressure supplied
to
injectors

Pulsation damper
Absorbs fuel pulsation

Throttle sensor
Detects throttle valve opening angle; sends signal
to
engine control unit
Integrated idle switch

Water thermo sensor
Detects coolant temperature;
sends signal
to
engine control unit

Water thermo switch
Detects radiator coolant temperature; sends signal
to
engine control unit ON: above 17°C (63°F)

76G04B-058
4B—43

4B FUEL SYSTEM
Operating time Fuel line pressure kPa
(kg/cm2, psi)
After starting: for 120
sec.
235-275
(2.4—2.8, 34—40)
After 120 sec, 186-226 (1.9-2.3, 27-33)
6. Restart the engine.
7. Check the fuel line pressure and operating times
as shown in the chart.
76G04B-127
Solenoid Valve (Pressure Regulator Control)
Inspection
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.
86U04A-098
Air filter
Apply 12V
Port (J)
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 the vacuum
hose A.
7. Check that air flows from the valve air filter.
86U04A-099
4B-56