fuel consumption MAZDA 626 1987 User Guide

4 A DECELERATION CONTROL SYSTEM
TROUBLESHOOTING
Check the condition of the wiring harness and connectors before checking the engine control unit
or switches.
FE 12Valve and F8 (ECE, Hong Kong and Singapore)—MTX
Possible cause
Page
Symptom

Anti-afterburn

valve
Dashpot Bypass
air
control
system
Idle

switch
main
air

bleed

control
system

Engine

control

unit

terminal
Possible cause
Page
Symptom

Anti-afterburn

valve
Dashpot Bypass
air
control
system
Idle

switch
main
air

bleed

control
system
E L M
Possible cause
Page
Symptom 4A—50 4A—50 4A—48 4A—93 4A—51 4A—88
Runs rough on deceleration 2 1 3 5 4
Afterburn in exhaust system 1 2 4 3 5 6
Poor fuel consumption 1 2 3
Fails emission test 7 6 1 2 3 4 5
High idle speed after warm up 1 2 3
Engine stalls during warm up 1
Rough idle during warm up 1
Poor acceleration, hesitation, or lack of power 1
76G04A-079
FE 12Valve and F8 (ECE, Hong Kong and Singapore)—ATX
Possible cause o> o 4-* uT u. E 3
(0 >
c k_ 3 •Q L-
2 ST c
o o "O at 0)
_>. c O
£ O
o w c o
• 1
\Page a •
C
3 i CO V S.
v>

5 E c ® 5 »
5 w a> in m
< BO M S «T 2 B D 2N
Symptom 4A—50 4A—48 4A—51 4A—93 4A—86
Runs rough on deceleration 2 3 1 5 4
Afterburn in exhaust system 1 2 3 4 5
Poor fuel consumption 1 2
Fails emission test 7 6 2 1 3 4 5
High idle speed after warm up 1 2
Engine stall during warm up 1
Rough idle during warm up 1
Poor acceleration, hesitation, or lack of power 1
76G04A-080
4A—46

DECELERATION CONTROL SYSTEM 4 A
FE 8Valve—Unleaded Fuel
Possible cause
\Page ^s^
Symptom

Slow

fuel
cut
system
Coast
enrichment
system
Idle

switch
Anti-afterburn
valve

Bypass

air
control

system
Dashpot
(only
MTX)
Engine
control
unit

terminal

Possible cause
\Page ^s^
Symptom

Slow

fuel
cut
system
Coast
enrichment
system
Idle

switch
Anti-afterburn
valve

Bypass

air
control

system
Dashpot
(only
MTX)
A C G I
Possible cause
\Page ^s^
Symptom 4A-53 4A-54 4A-93 4A-50 4A-48 4A-50 4A—91
Runs rough on deceleration 8 6 1 7 3 4 5 2
Afterburn in exhaust system 7 3 1 4 2 5 8 6
Poor fuel consumption 2 1 6 5 4 3
High idle speed after warm up 2 1 3
Fails emission test 4 2 1 5 3 6 7 8 9
76G04A-081
FE 8Valve (General)
Possible cause main air bleed control
solenoid valve
Engine control unit terminal
Possible cause main air bleed control
solenoid valve
MTX ATX
Possible cause main air bleed control
solenoid valve
E F B 2F j 21
Page 4A—51 4A—90 4A—89
Checking order 1 2
76G04A-082
F6 (Singapore)
Possible cause
X^Page
Symptom

Dashpot

(Only

MTX)
Anti-afterburn
valve

idle

switch
L
Coasting

leaner

solenoid

valve
Engine

control

unit

terminal

Possible cause
X^Page
Symptom

Dashpot

(Only

MTX)
Anti-afterburn
valve

idle

switch
L
Coasting

leaner

solenoid

valve
B D
Possible cause
X^Page
Symptom 4A—50 4A—50 4A—93 4A—56 4A—92
High idle speed after warm up 1
Runs rough on deceleration 1 2 3
Afterburn In exhaust system 5 4 1 2 3
Fails emission test 4 1 2 3
76G04A-083
4A—47

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
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4B-14
a> 4)
E
o
4B-1S
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0 <0 £
4B-16
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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 FUEL SYSTEM
TROUBLESHOOTING
Check
the
condition
of
the wiring harness and connectors before checking
the
sensors
or
switches.
Possible
cause
Page

V
S E
i
o

o V)
0
e
~
0)
Ju
»
•E
<»
CL
01
3
0
<0
1
£
Oxygen

sensor

s c V
in
V

P
o E k_

•E **
l_
h
O
v
w
Water
thermo
switch

Q.
E
3 Q.
u

Injector

£ 3 3 o d
aj
Engine
con-
trol unit terminal
< £
8
<
Q. Oxygen

sensor

£ t->
0)
>
M Water
thermo
switch
3
u.
Injector
3
u. 3C
3E
3B
Symptom 4B-94 4B-99 4B—98 4B-95 48—97 4B-97 4B-49 4B-S1 4B-48 4B-90 4B-90
Hard start
or
won't start (Cranks
OK)
5 4 1 3 2

Engine While warming
up
4 3 2 1 5

stalls After warming
up
1 3 2 4

Rough Idle While warming
up
4 3 2 1

Rough Idle After warming
up
1 2 4 3

Poor acceleration, hesitation,
or

lack
of
power
1 3 4 2

Runs rough
on
deceleration
1 2

Afterburn
in
exhaust system
1 2

Poor fuel consumption
5 6 4 3 2 1

Falls emission test
1 2

Engine stalls
or
rough after
hot
starting
1 3 2

76G04B-059
4B—44

4B DECELERATION CONTROL SYSTEM
TROUBLESHOOTING
Check the condition of the wiring harness and connectors before checking the sensor or switches below.
Note
Make the system inspection first. If no problem is found, continue with the next system
inspection of the Troubleshooting Guide. (Refer to page 4B—7 and 8.)
Possible
^^ cause
Symptom
Dashpot Water thermo
sensor
Electrical signal
inspection
(Injector)
Possible
^^ cause
Symptom 4B—67 4B—97 4B-66
High idle speed after warming up 1
Runs rough on deceleration 1 3 2
Afterburn in exhaust system 1 3 2
Poor fuel consumption 1 3 2
Fails emission test 1 3 2
76G04B-090
Electrical Signal Inspection (Injector)
1. Connect the SST between the wiring harness and
engine control unit.
2. Set 3C or 3E position on the SST.
Note
3C — For No. 2 and No. 4 injectors
3E — For No. 1 and No. 3 injectors
76G04B-091
0-6V 0-20V
3. Check that the indicator lamps alternately flash at
idle.
86U04A-125
4B—66

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
T O
a c OI '35
O
I o Tt
o in
a> in
8 c
o
o (A C 0) in
S o
I o
c $
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00 T-I O
T o I-ij
o in c at at o E « £
2 a
o>
o
e o •C H
I O
o at e 0) o>
o CM I o
E a> «-» in >• in a o (0 A •o a> d>
CM I o
Output solenoid valve
o> > <0 >
2
—.

§8 £ c
O O
(0
O

CVI I o
c 0 u « 01 w 3 a
o z «
> 73 >
"O o c a> o (/)
CM CM
o
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Q. CM
V >
CB >
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CM CM
O
oc (9 UJ, g
n >
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CO CM
O
o o •o w « a in «
2
s
5 •o o c »
o CO
CO CM
o
n
£
o in c a* (A c a> o>
o
CM
O
w q) t « s > c w QJ O)
"8 g> IS n « £
a> >
a >
T3 O C ai o CO
TT CM
o
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

7C VIC SYSTEM
COMPONENT DESCRIPTION
Component Function Remark
Dynamic chamber Provides chamber for VIC system operation Integrates one-way check valve
Engine control unit Monitors engine rpm, controls solenoid valve Unleaded fuel: ON at above 5200 rpm Leaded fuel: ON at above 5400 rpm
Intake manifold Provides short and long length of intake travel Integrates shutter valve
One-way check valve Holds vacuum in vacuum chamber Installed between dynamic chamber and vacuum chamber
Ne signal pick-up Detects crank angle at 180° intervals; sends signal to control unit Installed in distributor
Solenoid valve (Vlfc) Controls vacuum to shutter valve actuator
Shutter valve Closes short intake port
Shutter valve actuator Actuates shutter valve according to
vacuum from solenoid valve
76G04C-066
TROUBLESHOOTING
Check the condition of the wiring harness and connectors before checking the sensor 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
\Page\.
Symptom
Vacuum chamber (Vacuum leak)
Shutter valve actuator
One-way check valve
Solenoid valve (VIC) Engine control unit (1C)
System
Inspection
Possible cause
\Page\.
Symptom
Vacuum chamber (Vacuum leak)
Shutter valve actuator
One-way check valve Vacuum ' Electric signal | signal
Engine control unit (1C)
System
Inspection
Possible cause
\Page\.
Symptom 4C—42 4C—41 4C—43 4C—42 4C-98 4C—41
Rough idle
During warm up 2 3 4 — — — 1 Rough idle After warming up 2 3 4 — — — 1
Poor acceleration, hesitation,
or lack of power 6 5 7 2 3 4 1
Poor fuel consumption 6 5 7 2 3 4 1
76G04C-067
4C—40

FUEL SYSTEM
4C

TROUBLESHOOTING
Checking the condition of the wiring harness and connectors before checking the sensors or switches.
Note
If
no
problem
is
found, continue with inspection
of the
next system
of
Troubleshooting
Guide. (Refer
to
page 4C—10,
and 11)

Possible cause 0 CO £ O ** CO £ O "5
Page


o CO c 0> (A
S o c
w O M C
.fc <0 "o
^ o w c 0) <0 c « o>
Im O CO c w w
0>
!
41 10 o E k 0) £ **
d>
5 <0 O E ^ 0) £
w 0

Fuel
pump
Injector Fuel
pressure

Engine control
unit terminal
a. E 3 a
a> » c

Transfer

pump

sv
(4WS)
ha c o o
if Qj
«> S£

< g. X O £ 1-ID a 5
Fuel
pump
Injector Fuel
pressure

1Q 3C,3E 3F,3H 3B ID k_ H
Transfer

pump

sv
(4WS) 3
C
U.
3

Symptom *C—103 4C—110 4C—107 4C—104 4C—107 4C—106 4C-56 4C-57 4C-54 4C-98 40-59
Hard start
or
won't start (Cranks
OK)
— — —-— g — 1 7 — 2 8 6 3 4 5
Engine During warm
up
4 — — — 3 — — 2 1 — 5 — — — —
stalls After warm
up
1 — — — — — — 3 2 — 4 — — — —
Rough During warm
up
5 — — — 3 — — 2 1 — 4 — — — —
a> 3 Idle After warm
up
1 6 — — 4 — — 3 2 — 5 — — — —
•o a> •o (0 a> c -»
Poor acceleration, hesi-tation,
or
lack
of
power 1 — — 3 5 — — 4 2 — 6 — — — — •o a> •o (0 a> c -» Runs
rough on
deceleration 1 — — — — — — 2 — — 3 — — — —
Afterburn on deceleration 1 — — — — — — 2 — — 3 — — — —
Poor fuel consumption 6 — 5 — 4 — — 2 1 — 3 — — — —
Engine stalls
or
runs rough after hot starting 1 5 — — — — — 3 2 — 4 — — — —
Falls emission test — — 1 — — 2 — 3 — — 4 — — — —
Hard start
or
won't
start (Cranks
OK)
— — — — 9 — 1 7 — 2 8 6 3 4 5
Engine During warm
up
4 — — — 3 — — 2 1 — 5 — — — —
stalls After warm
up
1 — — — — — — 3 2 — 4 — — — —
Rough During warm
up
— — — 3 — — 2 1 — 4 — — — —
a> 3 Idle After warm
up
1 6 — — 4 — — 3 2 — 5 — — — —
•o a> •o a
Poor acceleration, hesi-tation,
or
lack
of
power 1 — — — 4 — — 3 2 — 5 — — — —
a> Runs rough on deceleration 1 — — — — — — 2 — — 3 — — — —
Afterburn on deceleration 1 — — — — — — 2 — — 3 — — — —
Poor fuel consumption 5 — — — 4 — — 2 1 — 3 — — — —
Engine stalls
or
runs rough after
hot
staring 1 5 — — — — — 3 2 — 4 — — — —
Falls emission test 1 ?
76G04C-089
4C—51

4C DECELERATION CONTROL SYSTEM
DECELERATION CONTROL SYSTEM
Distributor
(Ne signal)
Idle switch
QSO-Water thermo sensor
=5
A/C switch
Engine control unit
Detection of
fuel cut
condition Determi-
nation of
fuel cut
speed
* *
1
T
No.3

I
No.4
No.2
The fuel cut system is provided as a deceleration control system.
This system is to improve fuel consumption.
86U04A-121
4C—72

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