air condition MAZDA 626 1987 Repair Manual

4C EGR SYSTEM (UNLEADED FUEL)
TROUBLESHOOTING
Check the condition of the wiring harness and connectors before checking the sensors or switches.
Note
Make the system inspection first. If no problem is found, continue with inspection of the
next system of the Troubleshooting Guide. (Refer to pages 4C—10 and 11.)
Possible cause
Throttle
sensor
Solenoid valve
(EGR)
EGR
modula-
tor valve
EGR con-trol valve
Water
thermo
sensor
Water
thermo switch
Engine control unit
terminal
System in-spection
2N
Page 4C—104 4C—78 4C—79 4C—79 4C—107 4C—106 4C—98 4C—78
Checking order 8 2 4 3 6 5 7 1
76G04C-144
System Inspection
1. Start the engine.
2. Accelerate the engine while still cold and verify that
the diaphragm of the EGR control valve does not
move.
3. Warm up the engine to normal operating temper-
ature and run it at idle.
Warning
Be careful when checking the EGR control
valve, the surrounding area is very hot.
4. Accelerate the engine and check that the di-
aphragm of the EGR control valve moves.
Solenoid Valve (EGR)
1. Disconnect the vacuum hose from the vacuum
pipe.
2. Blow through the solenoid valve from vacuum hose
A.
3. Check that air flows from port B.
76G04C-146
4C-78

EEC SYSTEM
4C

TROUBLESHOOTING
Check
the
condition
of the
wiring harness
and
connectors before checking
the
sensors
or
switches.
Note
Make
the
system inspection first.
If no
problem
is
found, continue with inspection
of the

next system
of the
Troubleshooting Guide. (Refer
to
pages 4C—10
and 11.)

Possible cause
« > (0 >
£ O
S in
E 3 3

Solenoid
valve
(No.
1 purge
control)

Solenoid

valve
(No.
2 purge
control)

Two-way

check
valve

a>
>. >

i
S
i
^
3>
o

o CO k n
V
*
£

3
_
a
o
k. T-
a>
E»S 3
_
a
o
CM
£

£ O
S in o E tm a> £
w V
o ID C a> in o E k a> £ **
a>
Engine
control
unit
terminal

c o +s o a> a. w c
E a> O <0 >
Solenoid
valve
(No.
1 purge
control)

Solenoid

valve
(No.
2 purge
control)

Two-way

check
valve

>-
0)
£
£
1-
o

Q. d) o
fe
Z
o
ofe Z
O
(0 (0 $ 2P,20
in
(O
Page 4C—83 4C-84 4C-84 4C—84 4C-83 4C-85 4C-82 4C-83 4C-106 4C-107 4C—98 4C-81
Checking order (Unleaded fuel) 4 2 3 — 10 11 5 6 7 8 9 1
Checking order
(Leaded fuel) — — — 1 — 2
76G04C-152
System Inspection
1. Check
the
vacuum hose routing.
2. If there
is a
poor connection, clog,
or
leak, repair
or replace
as
necessary.
3. Warm
up the
engine
and run it at
idle.
4. Disconnect vacuum hose
A
from
No. 1
purge con-
trol valve
and
connect
the SST to the
hose.
86U04A-140
5. Increase
the
engine speed
to
above 2,500
rpm

and verify that
the
gauge shows more than
150

mmHg
(5.9
inHg).
6. If not correct, check the solenoid valve (No.
1
purge
control).
7. Reconnect hose
A to No. 1
purge control valve.
4C-81
76G04C-153

4C CONTROL SYSTEM
Output Devices
and
Engine Conditions (Unleaded fuel)

REMARK

*
Above

7,000

rpm:

fuel

cut

'Coolant

temp.:
below

50°C

(122°F)

41 Coolant
temp:

below

70°C

(158°F)

*2 Engine
speed
above
1,700
rpm
*3 Engine

speed:

1,500—3,500

rpm

*
During
hot

start

only

*
Engine
speed:
above

5,200

rpm

'Engine

speed:
above

3,000

rpm

'Delays

0.5
second

IGN:

ON

(ENGINE
NOT RUNNING)

No

injection

No bypass OFF
(main

fuel

pump

not
operated)
OFF
OFF
z
1

IDLE

(THROTTLE
VALVE
FULLY CLOSED)
Rich

and

i
lean
Sequential
(once

per

two

revolutions)
OFF

o en C3 UJ
z
"After

start-
ing:

ON

(Vacuum

cut) OFF
o

DECELE-
RATION
'Fuel

cut

L

Small
amount
of
bypass
air
N (1st
stage
operate:

o
o Ho 3 O CO CD > CO >
>; CO
CO c o
c o o

HEAVY
LOAD
•ST c
Closed

Small
amount
of
bypass
air

-co-CD CO
N (1st
stage
operate:

In CD 2? 03 a. o CD o> CO to "O c

*3 OFF (EGR)

o Ho 3 O CO CD > CO >
03 k-o CO c 03 CO z o *
CD c O) c 03 c o
c o o a 3

ACCELE-
RATION
Rich

o •*—• 3 o > CD
O

Small
amount
of
bypass
air

03 Q. O Q. E 3

ON

O
In CD 2? 03 a. o CD o> CO to "O c
ON
(EGR cut)
:F (Vacuum
to
pressure

regulatt

03 3 -C CO o
c 03 CS3 > X o o
z o * CO •o c CD Q. CD T3
C CO CD o "O 3= O c: 3 CO
LL LL o

MEDIUM
LOAD
WARM
Rich

and lean

|
Q. CD O
CD D
C CO E
CVJ.
z o fS *
*3 OFF (EGR)
:F (Vacuum
to
pressure

regulatt

E 3 3
c 03 i t 3 G, LL LL
T3 CD O c CO > "O <
C CO CD o "O 3= O c: 3 CO
LL LL o

MEDIUM
LOAD

COLD

ro
c CD 3 cr
z O "a CD a? CD CL o

F (2nd
stage
not
operated)
:F (Vacuum
to
pressure

regulatt

z o * O «

WARMING
UP

(DURING
IDLE)
Rich

CD CO c CD Q-O
o
c 3 CO O CO E CO
o c F (2nd
stage
not
operated)

tr O UJ
z o
O
LL z
Fixed

at

BTDC

12°

CRANKING
(COLD
ENGINE)
1
group
(twice

per

revolution)

CO
«
CD urn i CO
CO
LL LL O
LL O * « o o
LL LL o
Fixed
at

BTDC

6°

z o

SOLENOID
VALVE
(PRESSURE
REGU-

LATOR

CONTROL)

CC
o z o o iii z
o z 111

OUTPUT
DEVICE
FUEL

INJECTION

AMOUNT FUEL
INJECTION
TIMING
AIR

VALVE

'
ISC

VALVE
FUEL
PUMP

CONTROL
MAIN
POWER
CONTROL
SOLENOID
VALVE
(No.1
PURGE)
SOLENOID

VALVE

(NO.2

PURGE)
SOLENOID
VALVE
(EGR)
SOLENOID
VALVE
(PRESSURE
REGU-

LATOR

CONTROL)
SOLENOID
VALVE
(VARIABLE
INE
TIA
CONTROL)

> <
Ul oc oc o
£T u. O 1 z oc 3 m
oc o

OUTPUT
DEVICE
INJECTOR
BAC
VALVE
CONTROL
RELAY
SOLENOID
VALVE
(No.1
PURGE)
SOLENOID

VALVE

(NO.2

PURGE)
SOLENOID
VALVE
(EGR)
SOLENOID
VALVE
(PRESSURE
REGU-

LATOR

CONTROL)
SOLENOID
VALVE
(VARIABLE
INE
TIA
CONTROL)

tn z Ul (0 z Ul o >-X o
A/C

RELAY

IGNITER

z Ul (O
=5 o
IL oc <
76G04C-169
4C—94

CONTROL SYSTEM
4C

Output Devices
and
Engine Conditions (Leaded fuel)

REMARK

E Q
O O O r-»" CD > o n <

fuel
cut

'Coolant

temp.:

below

50°

(122°F)

*
During

hot
starting
only

*
Engine

speed:

above

5,400

rpm

'Delays

0.5

seconds

IGN:
ON
(ENGINE
I
NOT
RUNNING)

o
z
injection
No
bypass
OFF

(main

fuel

pump

not
operated)
OFF
LL
I

IDLE
(THROTTLE
VALVE
FULLY
CLOSED)
Rich

I
Sequential (once
per
two

revolutions)
"After

start-
ing:
ON

(vacuum

cut)
O

DECELE-
RATION

i

i
'Fuel

cut

•o CD CO "co" CD ts o to 3 o CO CD > CO
CO c o
c o o

HEAVY
LOAD
sz "co" c
O o CO CO CO Q. >. -O
O
CD Q. O CL E CL ® D
C CO F
o 08 3 u> £ CD 3 CO 0) CD
o to 3 o CO CD > CO
z

c o o c
B

ACCELE-RATION

ir o 3 0 > CD 1 O
C
O E CO
"CO
CD Q. O CL E CL ® D
C CO F
z

o 08 3 u> £ CD 3 CO 0) CD
CD e 3 SZ CO o
O * CO
c CD CL CD T3
c CO 8 "D

'
MEDIUM
LOAD
WARM
Normal

CD Q. CD O
E CO
z
O
o o_ O
E
3 3
o CO ^ LL LL O
E 3 3 O CO
•o "O <
c
3
m
LL LL o

'
MEDIUM
LOAD
COLD

.H C CD 3 CT
o_ O
E
3 3
o CO ^ LL LL O

z
o *

WARMING
UP

(DURING
IDLE)
Rich

CD CO

*Open

B
3
CO
O
CO
E
<®
LL
Fixed

at
BTDC
12°

CRANKING
(COLD
ENGINE)
1
group
(twice

per

revolution)

CO
«
0)
>,
u>n w-CO
o

OFF
Fixed

at

BTDC

6°
ENGINE
CONDITION
OUTPUT
DEVICE
FUEL
INJECTION

AMOUNT
'
FUEL
INJECTION

TIMING
AIR

VALVE
ISC
VALVE
FUEL
PUMP
CONTROL MAIN
POWER
CONTROL
SOLENOID
VALVE
(PRESSURE
REGU-

LATOR

CONTROL)
SOLENOID
VALVE
(VARIABLE
INER-
TIA
CONTROL)

(T ik 0 1 z DC 3
ffl

OC o tn

OUTPUT
DEVICE
INJECTOR
BAC
VALVE
CONTROL
RELAY
SOLENOID
VALVE
(PRESSURE
REGU-

LATOR

CONTROL)
SOLENOID
VALVE
(VARIABLE
INER-
TIA
CONTROL)

A/C

RELAY

IGNITER

Z Ul tn
£ o
ik DC <
76G04C-170
4C—95

4C CONTROL SYSTEM
Terminal Input Output Connection to Voltage (After warming-up) Remark Terminal Input Output Connection to Ign: ON Idle Remark
10 o Air flow sensor
(Burn-off control) Below 2.5V White burning off:
Approx. 8—12V
1P o
Control relay (Power supply circuit) Below 2.5V Ignition switch OFF:
Approx. 12V
1Q 0 Control relay (Fuel pump circuit) Approx. 12V Below 2.5V
1R
(L/F) O Knock sensor OV or 2—7V While knocking:
Approx. 0.001
1S — — — — —
1T o Ignition switch
(ON position) Approx. 12V
1U — — — — —
1V — — — — —
1W o Test connector Test connector grounded: OV Test connector not grounded: approx. 12V Green connector, 1-pin
1X o Igniter Approx. 12V *Approx.1V 'Engine Signal
Monitor: green and
red lights flash
2A (U/F) o V ref 4.5—5.5V
2B o Air flow sensor
(Ground) OV
2C — — Ground (E2) OV
2D (U/F) o Oxygen sensor OV 0-1.0V
• Cold engine: 0V at idle
• After warming-up: Increase engine speed: 0.7—1.0V Deceleration: 0—0.2V
2E o Air flow sensor
(Intake air mass) 1.0—1.6V 1.7—2.3V Increase engine speed: voltage increases
2F — — — .— —
2G (U/F) o Throttle sensor Accelerator pedal released: approx. 0.5V
Max. voltage (Throt-tle valve fully opened): approx. ,4.3V
2H (L/F) o Air flow sensor (Variable resister) 0-5V Depends on
adjustment
21 o Water thermo sensor Approx. 0.4V
Engine coolant
temp. 20°C (68°F):
approx. 2.5
2J o Intake air thermo sensor (Dynamic chamber)
Approx. 2.5V at 20°C (68°F)
2K o
Solenoid valve (Pressure regula-tor control)
For 120 sec. after ignition switch OFF - ON: below 2.5V
For 120. sec after starting: below 2.5V
During hot condi-tion: Coolant temp, above 70°C (158°F) Intake air temp, above 30°C (86°F) ...Unleaded fuel above 50°C (122°F) ...Leaded fuel
2K o
Solenoid valve (Pressure regula-tor control)
ADDrox. 12V Other conditions
2L — — — — —
Note
a) Terminal labeled "U/F" are only for unleaded fuel.
b)Terminal labeled "L/F" are only for leaded fuel.
4C-100

CONTROL SYSTEM 4C
AIR FLOW SENSOR
Visual Inspection
1. Remove the air hose.
2. Check the air flow sensor visually for the following:
a) Torn protection net (air cleaner side)
76G04C-183
b) Restricted protection net
76G04C-184
Output Voltage Inspection
1. Remove the rubber boot from the air flow sensor
connector.
2. Check terminal voltage with a voltmeter.
——^.Condition Terminal — ... Ign. switch;ON Engine running
A (Idle mixture) 0—5V
B (Power supply) Approx. 12V
C (Burn-off) OV
D (Air flow mass) 1.0-1,6V I 1.7V-5V
E (Ground) OV
F (Ground) 0V
6. If not correct, check the wiring harness for an open
or short circuit
7. If the wiring harness is OK, replace the air flow
sensor.
76G04C-185
4C-103

TROUBLESHOOTING GUIDE 4D
TROUBLESHOOTING GUIDE
Condition Condition Cause Remedy
Hard starting Fuel filter
Clogged Replace
Water or air in filter Repair
Fuel injection pump Faulty fuel cut solenoid Replace Incorrect injection timing Adjust
Air in pump Bleed
Faulty pump Replace
Fuel injection nozzle Seized needle valve Replace
Fuel dripping from nozzle Replace Incorrect valve opening pressure Adjust
Faulty glow plug Replace
Faulty cold start device Adjust or replace
Faulty supercharging system Refer to page 4D—10
Rough idle Fuel filter (Refer to "Hard starting") Fuel injection pump (Refer to "Hard starting")
Fuel injection nozzle
Seized needle valve Replace
Incorrect valve opening pressure Adjust
Improper mounting to nozzle holder Repair
Leakage of nozzle holder copper washer Replace
Fuel injection pipe Cranks Replace
Leaking from joint Repair
Improper idle speed adjustment Adjust
Engine knocking Incorrect injection timing Adjust
Low quality fuel Replace
Incorrect injection nozzle opening pressure Ajust
Seized injection nozzle needle valve Replace
Fuel dripping from injection nozzle Replace
Faulty supercharging system Refer to page 4D—10
High fuel Fuel injection pump consumption Incorrect injection timing Adjust consumption High idle speed Adjust, Inspect the dashpot
Fuel injection nozzle Incorrect valve opening pressure Repair
Fuel dripping from nozzle Replace
Leakage of nozzle holder copper washer Replace
Fuel leaking from connection Repair
Clogged fuel filter Replace
Clogged air cleaner Replace
Poor acceleration Fuel injection nozzle (Refer to "Hard starting")
Fuel injection pump (Refer to "Hard starting")
Fuel injection pipe (Refer to "Rough idle") Fuel filter (Refer to "Hard starting") Clogged air cleaner Clean or replace
Faulty supercharging system Refer to page 4D—10
Excessive exhaust Clogged air cleaner Clean or replace
smoke Improper injection timig Adjust
Faulty nozzle or nozzle holder Adjust or replace
Faulty supercharging system Refer to page 4D—10
76G04D-003
4D-3

SPARK PLUG 5
Slow Charge
1. Stop the engine
2. Turn all the accessories off.
3. Remove the negative battery cable.
4. Perform a slow charge (3.5A to 4.5A).
5. Add distilled water if necessary while charging.
6. Charge once more if the specific gravity is under
fully charged gravity.
4BG05X-010
SPARK PLUG
REMOVAL AND INSTALLATION
Note the following points:
1. When the high-tension lead is to be pulled off, be
sure to pull the boot itself, and not the wire.
2. Tighten the spark plugs to the specified torque.
Tightening torque: 15—23 N-m
(1.5—2.3 m-kg, 10.8—16.6 ft-lb)
76G05X-054
Wear and adhesion or cabon
INSPECTION
Check the following points. If a problem is found, re-
place the spark plug.
1. Damaged insulation
2. Worn electrodes
3. Carbon deposits
If cleaning is necessary, use a plug cleaner or a
wire brush. Clean the upper insulator also.
4. Damaged gasket
5. Burnt condition of spark insulator
6. If it is black with carbon deposits, either misfiring
due to improper proportions of gas and air or over-
heating of the plug may have occurred.
Plug gap:
FE (12VALVE) and FE DOHC Leaded fuel
model:
0.70—0.80 mm (0.028—0.031 in)
FE (8VALVE) and FE DOHC Unleaded fuel
model:
1.0—1.10 mm (0.039—0.043 in)
Others:
0.75—0.85 mm (0.030—0.034 in)
76G05X-005
5-9

TROUBLESHOOTING
7C

QUICK DIAGNOSIS CHART
How
to use
Quick Diagnosis Chart
1.
The
numbers indicate
the
order
of
inspection
for
troubleshooting.
2. Circled numbers indicate that
the
transaxle must
be
removed from
the
vehicle.
76G07C-013
Transaxle ON VEHICLE OFF VEHICLE
•

\ Inspection point
\
and
reference
\ page
Condition


7C-25
7C-26
7C-23
10—21
7C—23,24
Section

4A

7C-14
7C—20,22
10—lb
10-12 10—69
7C—5
Section

5

7C—58
7C-62
7C-70
7C-71
7C-55
7C-125
7C-54 7C-71
7C-66,

98

7C-68,

71
\ Inspection point
\
and
reference
\ page
Condition

ATF

level
and
condition

Selector

lever
Inhibitor
switch
and
wiring

^

Vacuum
diaphragm
and

piping

|

Kick-down
solenoid,
kick-down
switch
and
wiring
Engine

idle

speed

and

condition

Engine
stall

speed

Fluid

pressure

(Line

and
governor)
Control
valves

Governor

valve
Band
servo
Transaxle
air
check
Ignition
switch
and
starter
Front
clutch

Rear

clutch
Brake

band

Low

and
reverse
brake

Oil
pump Hydraulic
circuit

Torque

converter

One-way

clutch
Parking

linkage

Planetary
gear

I

Engine

starting
Engine does
not
start
in
N or P
range •
2 3
1

Engine

starting
Engine starts
in
ranges other than
N
and P
ranges •
1 2

Accelerating
Vehicle does
not
move
in
D
range (moves
in 1, 2 & R
ranges) •
• •
•
Accelerating
Vehicle does
not
move
in
forward ranges (moves
in R
range)
Ex-
tremely poor acceleration •
• 5
• •
© •
•
• ©
•
• •
•
Accelerating
Vehicle does
not
move
in R
range (moves
in
forward range) Extremely poor acceleration 1
2 •
•
• •
•
3 4
•
• 5
• ©
© •
©
• ©
•
• •
•
Accelerating
Vehicle does
not
move
in any
range 1
2 •
•
• •
•
3 4
•
• 5
• •
• •
•
© ©
•
• ©
•
Accelerating Slippage felt when accelerating 1
2 •
6
• •
•ST
CO
•
•
• 5
• •
• •
•
© ©
•
• •
• Accelerating
Vehicle moves
in
N
range
Accelerating
Excessive creep
Accelerating
No creep
at all
©
© •
•
© ©
•
• •
•
Accelerating
Low maximum speed
and
poor acceleration 1
2 •
•
• 7
3
4 6
•
5 •
• ©
© ©

No shifting

Does
not
shift from
1
st to 2nd
•
1 •
2
3 •
•
• 4
5
6 7
• •
© ©
•
• ©
•
• •
•

No shifting
Does
not
shift from
2nd to 3rd
•
1 •
2
3 •
•
• 4
5
6 7
•

No shifting

Does
not
shift from
3rd to 2nd
1
• •
2
• •
•
• 3
4
5 6
• ©
• ©
•
• ©
•
• •
•
76G07C-014
7C-9

7C TROUBLESHOOTING
ON VEHICLE OFF VEHICLE
-

\ Inspection point
\ and reference
\ page
Condition


LO
(O
CO CJ OJ CM I
I I
O
O
CJ
r-~
r—
7C-27
7C—23,24
Section

4A

7C—14
7C—20,22
7C-75

CO
O)
in
I
I I
o
o o
r—
r—
Section

5
CO CO
o
WON I
I I
o
o o
1— 1—
m i-
in co
S
IO
i-
1
1 1
o
o o
—
I—
7C—54
7C-71
7C-66,

98

7C—68,

71
\ Inspection point
\ and reference
\ page
Condition

A.TF

level
and

condition

Selector
lever
Inhibitor
switch
and
wiring

Vacuum

diaphragm
and

piping

Kick-down

solenoid,

kick-down

switch
and

wiring

Engine

idle
speed
and
condition
Engine
stall
speed
Fluid
pressure
(Line
and
governor)

Control

valves

Governor

valve
Band
servo

Transaxle

air
check
Ignition
switch
and

starter

Front

clutch

Rear

clutch

Brake

band

Low

and
reverse
brake
Oil pump Hydraulic
circuit
Torque
converter

One-way

clutch

Parking

linkage
Planetary
gear

No
shifting

Does
not
shift from 2nd
to
1
st or from
3rd to
1
st 1
• •
2
• •
•
• 3
4
5 6
•
No
shifting

Does
not
kick-down when accelerator
is
depressed
in 3rd
within
the
kick-down range 1
• •
3
2*
•
• 4
5
• •
• •
• ©
•
• ©
•
• •
•
No
shifting
Excessive engine speed when accelerated
in 3rd
due
to
delayed kick-down 5
• 6
• ©
• •
•
• ©
•
• •
• No
shifting

Does
not
shift from
3rd to 2nd
on
D to
2
range shift 1
2 •
5
6 •
• ©
• ®
•
• ®
•
• •
•
No
shifting

Does
not
shift from
3rd to 2nd
on
D to 1
range shift 5
7 6
• ©
• ®
•
• ®
•
• •
•

Shift

shock

Excessive
N to
D
range shift shock •
• •
2
• 1
•
3 4
•
• •
• •
© •
•
• •
•
• •
•

Shift

shock

Excessive
1
st
to
2nd shift shock 1
• •
2
• •
3
• 4
•
5 6
• •
• ©
•
• •
•
• •
•

Shift

shock

Excissive 2nd
to 3rd
shift shock •
• •
1
• •
•
2 3
•
4 5
• ©
• ©

Shift

shock

Vehicle braked when shifted from
1
st
to 2nd

Shift

shock
Vehicle braked when shifted from 2nd
to 3rd
1
• •
•
• •
•
• 3
.
2 •
•

Shift

shock

Vehicle braked when shifted
to
R range 1
• •
•
• •
•
• •
•
3 2
• •
© ©
•
• •
•
• ©
•
Shift

shock

Shift shock felt when accelerator
is
released
and
deceleration occurs •
1 •
2
3*
•
4 5
6
• •
• •
• •
•
• ©
•
• *
•

Shift

shock

Excessively large 2nd
to 1st
shift shock
in 1
range 1
• •
2
• •
3
4 5
•
• •
•
Shift

point

Excessively high
1st to 2nd
and 2nd
to
3rd shift 1
• •
2
3 •
•
4 5
6
• •
•
Shift

point

Excessively high
3rd to 2nd
and
2nd to
1
st shift point •
1 •
2
3 •
•
4 5
6
• •
• •
• •
•
• ©
•
• •
•
Shift

point
Kick-down operates
or
engine overruns when depressing
ped-
al
in 3rd
beyond kick-down speed limit
1
2 •
3
• •
•
4 5
6
• 7
•

Shift
sequence

Shifts directly from 1st
to 3rd
1
• •
•
• •
•
• 2
3
• 4
• •
• ©
•
• ©
•
• •
•

Shift
sequence
Shifts from
2nd to 1st or
2nd
to
3rd
in
2
range •
1 •
•
• •
•
2 3
•
• •
•
7C-10