1987 MAZDA 626 Workshop Manual

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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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

TROUBLESHOOTING WITH SST 4C
TROUBLESHOOTING WITH SST
Engine control unit
76G04C-011
When troubles occur in the main input devices or output devices, check for the cause with the SST
(Self-Diagnosis checker 49 H018 9A1 or Digital code checker 49 G018 9A0 with Adaptor har-
ness 49 9200 180)
Failure of individual input and output devices is indicated and retrieved from the control unit as mal-
function code numbers.
Note
The control unit constantly checks for malfunction of the input devices. But, the control
unit checks for malfunction of output devices only in a 3 second period after the ignition
switch is turned ON and the test connector is grounded.
4C—11

4C TROUBLESHOOTING WITH SST
Check connector: (Green, 6 pin)
49 H018 9A1
86U04A-011
Test connector: (Green, 1 pin)'
INSPECTION PROCEDURE
1. Connect the SST to the check connector. (Green,
6-pin) and the negative battery terminal.
2. Set the select switch to position A.
Note
The check connector is located at the rear of
the left side wheel housing.
3. Ground the test connector (Green, 1-pin) with a
jumper wire.
Note
The test connector is located near the Self-
Diagnosis Checker check connector.
86U04A-012
OO
uu
SELF-DIAGNOSIS CHECKER
MONITOR LAMP SELECT SW «

o o o
o
76G04C-012
4. Turn the ignition switch ON.
5. Verify that 88 flashes on the digital display and that
the buzzer sounds for three seconds after turn-
ing the ignition switch ON.
6. If 88 does not flash, check the control relay (refer
to page 4C—96), power supply circuit, and check
connector wiring.
7. If 88 flashes and the buzzer sounds continuously
for more than 20 seconds check the check con-
nector wiring, then replace the engine control unit
and perform steps 3 and 4 again.
8. Note the code numbers and check for the causes
by referring to the check sequences shown on
pages 4C—16 to 4C—24. Repair as necessary.
Note
Cancel the code numbers by performing the
after-repair procedure after repairing.
AFTER-REPAIR PROCEDURE
1. Cancel the memory of malfunctions by disconnect-
ing the negative battery cable and depress the
brake pedal for at least five seconds.
76G04C-013
4C-12

TROUBLESHOOTING WITH SST 4C
49 H018 9A1
negative battery cable
^ll
Test connector: (Green, 1 pin)
86U04A-015

Ignition switch:
ON

for six
seconds
76G04C-014
2. Connect the SST to the check connector.
3. Ground the test connector (Green, 1-pin) with a
jumper wire.
4. Turn the ignition switch ON for six seconds (do
not start the engine).
5. Start and warm up the engine, then run it at 2,000
rpm for two minutes.
6. Verify that no code numbers are displayed.
PRINCIPLE OF CODE CYCLE
Malfunction codes are determined as shown below
86U04A-017
1. Code cycle break
The time between warning code cycles is 4.0 sec (the time the light is off).
ON
OFF
1 cycle Malfunction code
cycle break
4.0 sec.
86U04A-018
4C—13

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