check engine MAZDA 626 1987 Manual PDF
[x] Cancel search | Manufacturer: MAZDA, Model Year: 1987, Model line: 626, Model: MAZDA 626 1987Pages: 1865, PDF Size: 94.35 MB
Page 404 of 1865
IDLE SPEED AND IDLE MIXTURE 4A
76G04A-063
76G04A-064
4. Turn the mixture adjust screw to adjust the CO con-
centration.
5. Recheck the idle speed.
6. Fit a new blind cap onto the mixture adjust screw.
Idle Mixture [FE 8Valve—Unleaded Fuel]
Adjustment of the idle mixture is normally un-
necessary.
But if it is necessary, adjust it as follows.
Note
Do not insert the exhaust gas analyzer into the
tail pipe.
Before adjust the idle mixture, check and set
the idle speed.
1. Disconnect the secondary air hoses.
2. Insert an exhaust gas analyzer into the hose and
plug it to prevent leakage.
3. Start the engine and run it at idle.
4. Measure the CO concentration.
5. Remove the blink cap from the mixture adjust
screw.
6. Turn the mixture adjust screw and adjust the CO
level.
CO concentration: 2.0 ± 0.5%
7. If the idle speed fails to meet specification as the
result of the above steps, adjust the idle.
8. Reconnect the secondary air hoses.
9. Fit a new blind cap onto the mixture adjust screw.
76G04A-065
4A-39
Page 405 of 1865
![MAZDA 626 1987 Manual PDF
4 A AUTO-RETURN CHOKE SYSTEM
AUTO-RETURN CHOKE SYSTEM
[FE 8VALVE—UNLEADED FUEL, MIDDLE EAST, and F6—GENERAL]
r ~ I
76G04A-066
An auto-return choke is adopted to prevent the catalytic convert](/img/28/57059/w960_57059-404.png "MAZDA 626 1987 Manual PDF
4 A AUTO-RETURN CHOKE SYSTEM
AUTO-RETURN CHOKE SYSTEM
[FE 8VALVE—UNLEADED FUEL, MIDDLE EAST, and F6—GENERAL]
r ~ I
76G04A-066
An auto-return choke is adopted to prevent the catalytic convert")
4 A AUTO-RETURN CHOKE SYSTEM
AUTO-RETURN CHOKE SYSTEM
[FE 8VALVE—UNLEADED FUEL, MIDDLE EAST, and F6—GENERAL]
r ~ I
76G04A-066
An auto-return choke is adopted to prevent the catalytic converter from over-heating because of over
use of the choke. This system opens the choke valve by causing the choke knob to return when the
engine coolant temperature is more than 67°C (153°F).
TROUBLESHOOTING
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting Guide. (Refer to pages 4A—16, 21, or 22)
Possible cause
" ^ Page
Symptom
System inspection Choke magnet Water thermo switch
Possible cause
" ^ Page
Symptom 4A—40 4A—41 4A—41
Checking order 1 2 3
76G04A-067
System Inspection
1. Make sure that the engine is cold and turn the ig-
nition switch ON.
2. Pull out the choke knob and check that it is held on.
3. Start the engine and check that the choke knob
returns during warming-up.
76G04A-068
4A—40
Page 407 of 1865
![MAZDA 626 1987 Manual PDF
4A PTC HEATER SYSTEM
PTC HEATER SYSTEM
[FE
and
F8 engine (except Middle
East)]
76G04A-071
The PTC heater system consists of the PTC heater, relay, and water thermo switch. The system is
desig](/img/28/57059/w960_57059-406.png "MAZDA 626 1987 Manual PDF
4A PTC HEATER SYSTEM
PTC HEATER SYSTEM
[FE
and
F8 engine (except Middle
East)]
76G04A-071
The PTC heater system consists of the PTC heater, relay, and water thermo switch. The system is
desig")
4A PTC HEATER SYSTEM
PTC HEATER SYSTEM
[FE
and
F8 engine (except Middle
East)]
76G04A-071
The PTC heater system consists of the PTC heater, relay, and water thermo switch. The system is
designed to prevent carburetor icing when the engine operating temperature is low t assure optimum
driveability.
TROUBLESHOOTING
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting Guide. (Refer to pages 4A—19, —20, or—22)
FE 8Valve—Unleaded Fuel
Possible cause System
inspection
Water thermo switch (intake manifold)
PTC heater
Water
thermo
switch
(Radiator)
PTC heater
relay
Page 4A—43 4A—41 4A—43 4A—95 4A—44
Checking order 1 2 3 4 5
Except FE 8Valve—Unleaded Fuel
Possible cause System inspection
Water thermo switch (Radiator)
PTC heater PTC heater
relay
Page 4A—43 4A—95 4A—43 4A—44
Checking order 1 2 3 4
76G04A-072
4A-42
Page 408 of 1865
PTC HEATER SYSTEM 4A
System Inspection
Except FE 8Valve—Unleaded Fuel
1. Connect a voltmeter to the PTC heater connector.
2. Start the engine and measure the voltage.
Specification
Radiator coolant
temperature Below 17°C (63°F) Above
17°C (63°F)
Voltage Approx. 12V ov
76G04A-073
FE 8Valve—Unleaded Fuel
1. Start the engine.
2. Connect a voltmeter to the PTC heater connector
terminals and measure the voltage.
Voltage
Engine coolant
temperature
Below 67°C (152°F)
Above 67°C (152°F)
Radiator coolant temperature Below 17°C (63°F) Above 17°C (63°F) —
Terminal BrB Approx.
12V
OV OV Terminal BrW
Approx.
12V Approx. 12V OV
76G04A-074
PTC Heater
Except FE 8Valve—Unleaded Fuel
1. Disconnect the PTC heater connector.
2. Check for continuity of the heater with an
ohmmeter.
76G04A-075
FE 8Valve—Unleaded Fuel
1. Disconnect the PTC heater connector.
2. Check for continuity between terminal wire (BrW)
and a ground.
3. Check for continuity between terminal wire (BrB)
and (B).
76G04A-076
4A—43
Page 411 of 1865
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
Page 412 of 1865
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
Page 413 of 1865
![MAZDA 626 1987 Manual PDF
4 A DECELERATION CONTROL SYSTEM
BYPASS AIR CONTROL SYSTEM
FE and F8 [Except General and Middle East]
E -tr Air bypass solenoid valve
I
Engine
control
unit
FE 8 Valve — Unleaded fuel
J
f^](/img/28/57059/w960_57059-412.png "MAZDA 626 1987 Manual PDF
4 A DECELERATION CONTROL SYSTEM
BYPASS AIR CONTROL SYSTEM
FE and F8 [Except General and Middle East]
E -tr Air bypass solenoid valve
I
Engine
control
unit
FE 8 Valve — Unleaded fuel
J
f^")
4 A DECELERATION CONTROL SYSTEM
BYPASS AIR CONTROL SYSTEM
FE and F8 [Except General and Middle East]
E -tr Air bypass solenoid valve
I
Engine
control
unit
FE 8 Valve — Unleaded fuel
J
f^^n
Ignition coil
Idle switch
76G04A-084
The bypass air control system consists of the bypass solenoid valve, idle switch, ignition coil, and en-
gine control unit.
This system opens the bypass air passage to the intake manifold during deceleration above ap'prox.
2,300 rpm (ECE, Hong Kong, and Singapore), or above approx. 3,500 rpm (FE 8 Valve—Unleaded
fuel).
Note
Make the system inspection first. If no problem is found, continue with the next inspec-
tion of the Troubleshooting. (Refer to page 4A—46 or 47.)
Troubleshooting
Possible cause System inspection Air bypass solenoid valve
Page 4A-48 4A-49
Checking order 1 2
/
/o fcl i /o ' jXj^/* J
V\ i \\ I M
p)
/ Terminal AGL...Leaded Fuel
L LB...FE 8 Valve—Unleaded Fuel
System Inspection
1. Warm up the engine and run it at idle.
2. Connect a tachometer.
3. Disconnect the bypass air hose from the air cleaner
and place a finger over the hose opening.
76G04A-085
4A—48
Page 414 of 1865
DECELERATION CONTROL SYSTEM 4 A
FE 8 Valve
FE 12 Valve
76G04A-086
FE 8 Valve
FE 12 Valve
76G04A-087
FE 8 Valve
J3P®
FE 12 Valve
»f^"ilS
(A)
76G04A-088
FE 8 Valve
FE 12 Valve
5. Increase the engine speed to 4,000 rpm.
6. Check that no vacuum is felt.
7. Quickly decrease the engine speed and check that
vacuum is felt during above specified engine
speed.
Specification
FE 8 Valve Approx. 3,500 rpm
Others Approx. 2,100 rpm
Air Bypass Solenoid Valve
1. Disconnect air hose (A) from the air cleaner.
2. Disconnect air hose (B) from the intake manifold.
3. Disconnect the connector from the solenoid valve.
4. Blow air through the solenoid valve from (A) and
check that air does not come out from (B).
5. Apply 12V to the connector terminal with jumper
wire.
6. Blow air through the solenoid valve from (A) and
check that air comes out from (B).
7. If the solenoid valve does not operate properly, re-
place it with a new one.
76G04A-089
4A—49
Page 415 of 1865
4 A DECELERATION CONTROL SYSTEM
76G04A-090
76G04A-091
DASHPOT (MTX)
Inspection
1. Suddenly move the throttle lever and check that
the dashpot rod comes out to its full stroke with
the throttle lever.
2. Release the throttle lever and check that it returns
slowly to the idle position after contacting the dash-
pot rod.
Adjustment
1. Warm up the engine to the normal operating tem-
perature and run it at idle.
2. Connect a tachometer to the engine.
3. Increase the engine speed to 3,000 rpm.
4. Slowly decrease the engine speed and check that
the dashpot rod touches the lever at 2,200 ±100
rpm.
5. If not within specification, loosen the locknut and
turn the dash pot to adjust.
ANTI-AFTERBURN VALVE
Inspection
1. Start the engine and let it idle.
2. Block the intake port of the anti-afterburn valve and
check that the engine speed does not change.
3. In crease the engine speed and quickly decelerate.
4. Check that air is pulled into the intake port for
1
—2
seconds after the accelerator is released.
76G04A-092
4A—50
Page 417 of 1865
4 A DECELERATION CONTROL SYSTEM
Solenoid valve (for main air bleed control system)
76G04A-094
76G04A-095
76G04A-191
System Inspection
1. Disconnect the vacuum switch connector.
2. Make sure that radiator coolant temperature is be-
low 17°C (63°F).
3. Disconnect the upper vacuum hose from the sole-
noid valve.
4. Place a finger over the solenoid valve open port
and check that vacuum is not felt when engine is
running.
5. Warming up the engine.
6. Place a finger over the same open port of the sole-
noid valve and check that weak vacuum is felt.
7. Reconnect the vacuum switch connector.
8. Check that weak vacuum is felt at the open port
of the solenoid valve at idle.
9. Accelerate the engine rapidly and check that vacu-
um is not felt.
Solenoid Valve (A/C)
1. Disconnect vacuum hose A (White) from the car-
buretor.
2. Disconnect vacuum hose B from the solenoid
valve.
3. Disconnect the solenoid valve connector.
4. Blow air through the valve from hose A and check
that it comes out of port C.
5. Apply 12V and ground to the solenoid valve with
jumper wires.
6. Blow air through the valve from hose A and check
that air not come out.
7. Replace if necessary.
76G04A-192
4A—52