4C CONTROL SYSTEM
RELATIONSHIP CHART
Output Devices
and
Input Devices (Unleaded fuel)
IGNITION SWITCH
(ON POSION) X X X X X O X X X X X X X X O
TEST CONNECTOR X X X O X X X X X X X X X O X
ELECTRICAL LOAD CONTROL UNIT X X X o X X X X X X X X X X X
P/S PRESSURE SWITCH X X X o X X X X X X X X X X X
A/C SWITCH X X X o X X X X X X X X O X X
IGNITION SWITCH
(STA POSITION) O O X o O X X X X O X X X O X
NEUTRAL
AND
CLUTCH SWITCH O X X o X X X X X X X X X X X
OXYGEN SENSOR o X X X X X X X X X X X X X X
WATER THERMO
SWITCH (RADIATOR) o X X X X X X X o X X X X X X
INTAKE
AIR
THERMO SENSOR X X X X X X X X X O X X X X X
WATER
THERMO SENSOR o X X o X X o o O O X X X O o
IDLE SWITCH o X X o X X X X X o X X X O X
THROTTLE SENSOR o X X X X X X X O X X X X o X
AIR FLOW SENSOR o X X X X X X o X X X X X o O
Ne SIGNAL o o X O o X X O O O o o X o O
G SIGNAL X O X X X X X X X X X X X X X
\
INPUT
DEVICE
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
REGULATOR
CONTROL)
SOLENOID
VALVE
(VARIABLE
INERTIA
CONTROL)
OXYGEN
SENSOR
RELAY
I A/C
RELAY
IGNITER
AIR
FLOW
SENSOR
(BURN-OFF)
\
INPUT
DEVICE
OUTPUT
DEVICE
INJECTOR
BAC
VALVE
CONTROL
RELAY
SOLENOID
VALVE
(No.1
PURGE)
SOLENOID
VALVE
(No.2
PURGE)
SOLENOID
VALVE
(EGR)
SOLENOID
VALVE
(PRESSURE
REGULATOR
CONTROL)
SOLENOID
VALVE
(VARIABLE
INERTIA
CONTROL)
OXYGEN
SENSOR
RELAY
I A/C
RELAY
IGNITER
AIR
FLOW
SENSOR
(BURN-OFF)
76G04C-167
4C—92
CONTROL SYSTEM 4C
Output Devices and In put Devices (Leaded fuel)
IGNITION SWITCH
(ON POSITION) X X X X X O X X X X O
TEST CONNECTOR X X X O X X X X X O X
KNOCK SENSOR X X X X X X X X X o X
ELECTRICAL LOAD
CONTROL UNIT X X X O X X X X X X X
P/S PRESSURE SWITCH X X X o X X X X X X X
A/C SWITCH X X X o X X X X O X X
IGNITION SWITCH (STA POSITION) O O X o O X O X X O X
NEUTRAL AND
CLUTCH SWITCH O X X o X X X X X X X
INTAKE AIR THERMO SENSOR X X X X X X O X X X X
WATER THERMO SENSOR O X X o X X O X X O o
IDLE SWITCH o X X o X X o X X O X
VARIABLE RESISTOR (IN AIR FLOW SENSOR) o X X X X X X X X X X
AIR FLOW SENSOR o X X X X X X X X O O
Ne SIGNAL o o X O o X O o X o O
G SIGNAL X O X X X X X X X X X
INPUT
DEVICE
OUTPUT
DEVICE
FUEL
INJECTION
AMOUNT
FUEL
INJECTION
TIMING
AIR
VALVE
ISC
VALVE
FUEL
PUMP
CONTROL
MAIN
POWER
CONTROL
SOLENOID
VALVE
(PRESSURE
REGULATOR
CONTROL)
SOLENOID
VALVE
(VARIABLE
INERTIA
CONTROL)
A/C
RELAY
IGNITER
AIR
FLOW
SENSOR
(BURN-OFF)
INPUT
DEVICE
OUTPUT
DEVICE
INJECTOR
BAC
VALVE
CONTROL
RELAY
SOLENOID
VALVE
(PRESSURE
REGULATOR
CONTROL)
SOLENOID
VALVE
(VARIABLE
INERTIA
CONTROL)
A/C
RELAY
IGNITER
AIR
FLOW
SENSOR
(BURN-OFF)
76G04C-168
4C—93
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
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
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
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
EGI MAIN FUSE
Inspection
Check the continuity of EGI main fuse.
69G04A-161
CONTROL RELAY
Power Supply Circuit
1. Check that a "clicking" sound is heard at the con-
trol relay when turning the ignition switch ON and
OFF.
Note
The control relay is located under the center
console.
76G04C-171
2. Apply 12V to the 2B terminal and ground the 2D
terminal of the control relay.
3. Check voltage at the terminals with an voltmeter.
terminal
Terminals Grounded Not grounded
2C 12V OV
2E 12V OV
76G04C-172
From EGI From '9' From Ig. main fuse switch (ON) / switch
(ST)
To C/U / 9round To main To injector fuel Pump
Fuel Pump Circuit
1. Apply 12V and a ground to the terminals described
below and check the terminals with an ohmmeter
or voltmeter.
Terminal applied 12V
Terminal
grounded
Terminal checked
Correct condition
1B 1D 2F-1A Continuity
2F 1C 1A ADDrox.12V
76G04C-173
4C-96
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
4D
FUEL AND EMISSION
CONTROL SYSTEM
(DIESEL)
OUTLINE 4D— 2
SPECIFICATIONS 4D— 2
TROUBLESHOOTING GUIDE 4D— 3
ON-VEHICLE MAINTENANCE 4D— 4
AIR CLEANER ELEMENT 4D— 4
WATER DRAINING 4D— 4
AIR BLEEDING 4D— 4
INJECTION TIMING 4D— 5
IDLE SPEED 4D— 6
EXHAUST SMOKE 4D— 6
INTAKE AIR SYSTEM 4D— 7
STRUCTURAL VIEW 4D— 7
AIR DUCT AND AIR CLEANER 4D— 8
INTAKE MANIFOLD 4D— 9
SUPERCHARGING SYSTEM (RF-CX) 4D-10
TROUBLESHOOTING GUIDE 4D—10
ON-VEHICLE INSPECTION 4D—11
COMPREX SUPERCHARGER 4D—13
STARTING VALVE 4D—15
INTERCOOLER 4D—16
BOOST AIR TEMPERATURE SENSOR 4D—17
EXHAUST SYSTEM 4D—18
STRUCTURAL VIEW 4D—18
EXHAUST MANIFOLD 4D—19
EXHAUST PIPE AND MAIN SILENCER .... 4D—20
FUEL SYSTEM 4D—21
STRUCTURAL VIEW 4D—21
FUEL FILTER 4D—22
SEDIMENTER (GENERAL) 4D—22
WATER LEVEL SENSOR 4D—23
INJECTION PUMP 4D—24
INJECTION NOZZLE 4D—31
FUEL TANK 4D—34
76G04D-001
4D OUTLINE
OUTLINE
The Mazda 626 offers two diesel engines; a Comprex supercharged RF-CX engine, and a normally
aspirated RF-N engine.
SPECIFICATIONS
—Engine model
Item ———
ECE UK, GENERAL —Engine model
Item ——— RF-CX RF-N
Fuel tank Capacity liters (US gal, Imp gal) 60 (15.9, 13.2)
Fuel filter Type Cartridge, paper element
Sedimenter Type With detector
Injection pump
Type Bosch VE distributor
Injection pump
Manufacturer Diesel Kiki Co,, Ltd.
Injection pump
Direction of rotation Clockwise Injection pump
Drive method Timing belt
Injection pump
Plunger diameter mm (in) 9.0 (0.35) 8.0 (0.31)
Injection pump
Cam lift mm (in) 2.2 (0.087)
Injection nozzle Type Throttle Injection nozzle
Injection pressure kPa (kg/cm2, psi) 13,240 (135 , 1,920)
Injection timing ATDC
1
° TDC 0°
Idle speed rpm 720 _+f0
Fast idle speed (A/C ON) rpm 700-750
Cold start device Engine speed rpm 1.100 Cold start device
Advance degree 6°
Air cleaner Type Cartridge, paper element Air cleaner Type
Wet Dry
PCV system Type Open Closed
76G04D-002
4D—2