fuel MAZDA 626 1987 Workshop Manual

4C OUTLINE
Exhaust System
Unleaded Fuel
Leaded Fuel
76G04C-006
4C—6

Hose color:
G ....Green
B ....Black
W ....White
Br....Brown
L ....Blue
R ....Red
EGR modulator valve*1
EGR control valve*1
Y ....Yellow O ....Orange
Pressure regulator
Solenoid valve (EGR)
Shutter valve actuator
Solenoid valve*1
(No.1 purge control)
Solenoid valve (PRC)
Solenoid valve (VIC)
Solenoid valve*1
(No.2 purge control)
Canister
*1....Unleaded fuel only

4C OUTLINE
SPECIFICATIONS
Item Engine type Unleaded Fuel Leaded Fuel
Idle speed rpm 750 ± 50
Throttle body
Type Horizontal draft (2-barrel)
Throat diameter mm (in) No. 1 46 (1.8) Throat diameter mm (in) No. 2 40 (1.6)
Fuel pump
Type Impeller (in tank)
Output pressure kPa (kg/cm2, psi) Main pump: 441-588 (4.5—6.0, 64—85) Transfer pump: 20—25 (0.20—0.25, 2.8—3.6)
Feeding capacity cc (cu in)/10 sec. Main pump: More than 220 (13.4) Transfer pump: More than 190 (11.6)
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
Type High-ohmic
Type of drive Voltage
Resistance G 12--16
Injection amount cc (cu in)/15 sec. 66-91 (4.03-5.55)
Idle speed control valve
Solenoid resistance a 6.3--9.9
Fuel tank
Capacity liters (US gal, Imp gal) 60 (15.9, 13.2), 57 (15.0, 12.5): 4-wheel steering vehicle
Air cleaner
Element type Dry
Fuel
Specification Unleaded (95 RON or more) Leaded or unleaded fuel
(95 RON or more)
76G04C-008
4C-8

TROUBLESHOOTING GUIDE 4C
TROUBLESHOOTING GUIDE
This troubleshooting guide shows the malfunction numbers and the symptoms of various failures.
Perform troubleshooting as described below.
Input sensors and switches
Possible cause
Page
Symptom and No. CO
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Output solenoid valve
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Fault Indicated by SST
Code No. 02 03 05 *i 08 09 11 12 *2 15 • 2 17 *2 25 26 *2 27 *2 28 • 2 34 36 • 2 41
Hard start or won't start
(Cranks OK)
Engine stalls
Rough
Idle
During warm up
After warm up
During warm up
After warm up
High idle speed after warm up
Poor acceleration, hesita-tion or lack of power
TROUBLESHOOTING PROCEDURE
Note
Code No. Is to quickly determine which system or unit may be at fault by use of the SST. (Self-Diagnosis Checker 49 H018 9A1 or Digital Code Checker 49 G018 9A0 with Adaptor harness 49 9200 180)
1st: Check input sensors and output solenoid valves with the SST. (Refer to
page
AC—11.)

2nd: Check other switches with the SST. (Refer to page AC—25.)
3rd: Check the following items:
Electrical system
1) Battery condition 2) Fuses
Runs rough on deceleration
Afterburn in exhaust
system
9
10
Poor fuel consumption
Engine stalls or runs
rough after hot starting
11
12
Knocking
Fuel system
1) Fuel level
2) Fuel leakage 3) Fuel filter 4) Idle speed (with test connec-tor grounded)
Engine
1) Compression 2) Overheating
Ignition system 1) Ignition spark
2) Ignition timing (with test connec-tor grounded)
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 4C—10.)
*1..
*2„
.Leaded fuel
.Unleaded fuel
76G04C-009
4C—9

4C TROUBLESHOOTING GUIDE
The Troubleshooting Guide lists the systems most likely to cause
a
given symptom. After finding which
system(s)
to
check, refer
to the
pages shown
for
detailed guides.
iSystem
S UJ 1-tn > tn

INTAKE

AIR
SYSTEM
FUEL
SYSTEM

o oc a
_i o oc 1-z o o oc o i-<
-i
o UJ OC Ul oc 3 (0 tn Ul oc a.
IDLE

SPEED
CONTROL
(ISC)
SYSTEM
ELECTRONIC
SPARK
ADVANCE

(ESA)

CONTROL
SYSTEM

EXHAUST

GAS
RECIRCULATION

(EGR)

SYSTEM

EVAPORATIVE

EMISSION

CONTROL
(EEC)
SYSTEM
POSITIVE
CRANKCASE
VENTILATION
(PCV)
SYSTEM
DECELERATION
CONTROL
SYSTEM

EXHAUST

SYSTEM

VARIABLE

INERTIA
CONTROL
(VIC)
SYSTEM

Page

4C—31 4C—49 4C—68 4C—44 4C—75 4C—77 4C—80 4C—86 4C—72 4C—87
&
89
4C—39
2 3 2 — — 1 — — — — — —
3
4 3 — 1 — 2 — _ _ — — 3 5 4 — 2 — 3 — 1 — — —
4 5 4 -1 — 3 — 2 — — -4 6 5 — 2 — 3 4 1 — — —
o z 5 2 3 — 1 — — — — — — —
E o 6 3 4 — — — 1 2 — — 6 5
Q-E >> 7 4 3 — 2 — — — — 1 — —
(0 8 3 4 — 1 — — — — 2 — —
9 — 2 — — — 3 — — 1 5 4
10 — 2 1 — — — — — — — —
11 — — — — 1 — — — — — —
12 6 7 — 4 — 2 5 _ 3 1
76G04C-010
The numbers
of the
list show
the
priorities
of
inspections, from
the
most possible system
to
that with
the lowest possibility.
These were determined
on the
following basis:
• Ease
of
inspection
•
Most possible system
•
Most possible point
in
system
4C—10

4C TROUBLESHOOTING WITH SST
2. Second digit of malfunction code (ones position)
The digit in the ones position of the malfunction code represents the number of times the buzzer
is on 0.4 sec during one cycle.
ON
OFF
1 cycle Malfunction code
1 2 3 cycle break
Malfunction
code: 03
n^j
0.4 0.4 sdc. sec.
4.0 sec.
76G04C-015
3. First digit of malfunction code (tens position)
The digit in the tens position of the malfunction code represents the number of times the buzzer
is on 1.2 sec during one cycle.
It should also be noted that the light goes off for 1.6 sec. between the long and short pulses of
the buzzer.
1 cycle Malfunction code
1 2
~U 0.4
1.2 sec. sec h
1 2|
flfl
First digit
1.6 sec.
cycle break
Malfunction
code: 22
nr
4.0 sec.
Second
digit
76G04C-016
CODE NUMBER
Malfunction display
Sensor or
subsystem Self-diagnosis Fail-safe Malfunction
code no.
Malfunction code output signal pattern
Sensor or
subsystem Self-diagnosis Fail-safe
02 o°nfJLJJL
Ne signal No Ne signal from crank angle sensor during craking
03 oppJUllUl
G signal No G signal Cancels sequencial
injection
05
Knock sensor (only
leaded fuel)
Open or short circuit • Retards ignition timing 4°
76G04C-017
4C—14

4C IDLE ADJUSTMENT
76G04C-048
Idle speed
Automatic
Control
Function
Engine Control Unit
76G04C-049
76G04C-050
3. Remove the blind cap and adjust the initial idle
speed to specification by turning the air adjust
screw.
Initial idle speed: 750 ± 50 rpm
4. After adjusting the idle speed, install the blind cap
and disconnect the jumper wire from the test con-
nector.
5. Recheck the idle speed.
6. If not within specification, check the idle speed con-
trol (ISC) system.
IDLE MIXTURE (Unleaded Fuel)
An automatic compensation function for air/fuel
mixture is built into the engine control unit, it
is not necessary to check and adjust the idle
mixture.
IDLE MIXTURE (Leaded Fuel)
Note
Before checking or adjusting the idle mixture,
check and adjust the idle speed, if necessary.
1. Insert a gas analyzer pick-up into the tail pipe.
2. Check that the CO and HC concentrations are with-
in specification.
CO concentration: 1.5 ± 0.5%
HC concentration: Less than 1,000 PPM
3. If the CO or HC concentration is not within specifi-
cation, turn the adjust screw
with
the SST to adjust.
76G04C-051
4C-30

4C INTAKE AIR SYSTEM
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 4C—52.)
Remove in the sequence shown in the figure, referring to the removal note.
1. Air cleaner
2. Air flow sensor
3. Air hoses
4. Connectors (Idle switch,
ISC, Throttle sensor)
5. Water hoses
6. Vacuum hoses
7. Accelerator cable
8. Throttle body
9. Gasket
10. PCV hose
4C-32
11. Vacuum pipe assembly
(Unleaded fuel)
12. Dynamic chamber brackets
13. Connectors (Knock sensor,
Intake air thermo sensor)
14. Dynamic chamber
15. One-way check valve
16. Gasket
17. Wiring harness
(for injectors)
18. Fuel hoses
76G04C-053
19. Delivery pipe assembly
mounting bolt.
20. Heat insulator
21. Injectors
22. Delivery pipe assembly
23. EGR pipe
24. Intake manifold bracket
25. Solenoid valve
26. Intake manifold
27. Gasket
28. Air duct
29. Resonance chamber

INTAKE AIR SYSTEM 4C
76G04C-054
76G04C-055
76G04C-056
Removal Note
Water hose
Before disconnecting the water hose, drain two liters
of engine coolant.
Delivery pipe assembly.
1. Separate the fuel return pipe from the delivery pipe
assembly.
2. Remove the delivery pipe assembly and the fuel
return pipe.
PARTS INSPECTION
Air Cleaner Element
1. Check the condition of the air cleaner element.
2. Blow out the dust with compressed air, if
necessary.
Caution
a) The air cleaner must be replaced at the in-
tervals outlined in the maintenance
schedule.
b) Never drive the vehicle without the air
cleaner element, otherwise, damage to the
air flow sensor (hot wire) will occur.
c) Never use an oil permeated air cleaner ele-
ment, otherwise, contamination of the hot
wire will occur.
4C—33

4C INTAKE AIR SYSTEM
Installation Note
Water hose spring clamps
Face the clamp end as shown in the figure.
Gasket
Use new gaskets at the intake manifold, dynamic
chamber, and throttle body.
86U04A-056
• . v 1
Engine 1 Ml' ' •-
hanger ^ •
• i::£?^Solenoid valve bracket
Air cleaner. r^I. ^jUvW;
Th V
Ground harnesses
Make sure that the ground harnesses are tightened
securely at the following positions.
(1) Air cleaner upper case
(2) Solenoid valve braket
(3) Engine hanger
76G04C-062
Solenoid valve connectors
Connect the solenoid valve connectors at the posi-
tions shown in the figure.
76G04C-063
Inspection after installation
1. After completing installation, fill up the engine with
the specified engine coolant.
2. Warm up the engine and run it at idle.
3. Check for any vacuum, coolant, or fuel leaks.
76G04C-064
4C-38