1987 MAZDA 626 fuel filter

4C FUEL SYSTEM
BW B
11. If not correct, check the voltage at terminals of the
fuel pump control unit.
76G04C-109
76G04C-110
86U04A-101
Fuel pump
Fuel filter
Bracket
76G04C-111
Terminal (wire) Voltage
A(B) Approx. 12V
C (BW) OV
12. If the voltages are correct, replace the fuel pump
control unit.
13. If not correct, repair the power supply circuit or the
ground circuit for the fuel pump control unit.
REPLACEMENT
Caution
A)Before performing the following procedure,
release the fuel pressure from the fuel sys-
tem to reduce the possibility of injury or fire.
(Refer to page 4C—52.)
b)When servicing the fuel system, keep
sparks, cigarettes, and open flames away
from the fuel.
Fuel Pump
1. Remove the rear seat and disconnect the fuel
pump connector.
2. Remove the service hole cover.
3. Disconnect the fuel hoses.
4. Remove the fuel pump and fuel tank gauge as-
sembly.
5. Replace the fuel pump.
Caution
Secure the fuel pump terminals and fuel hoses
tightly.
6. Install in the reverse order of removal.
4C—60

4C FUEL SYSTEM
^ Pulsation
damper
76G04C-121
Pulsation damper
—
Delivery pipe
76G04C-122
Fuel hose
,Fuel pump
-Intank filter
76G04C-123
Insulator
f f r—
/ 0 DM

•
II r
O - ring
Grommet
Manifold
Delivery pipe
Pressure Regulator
1. Remove the engine hanger.
2. Disconnect the vacuum hose and fuel return hose.
3. Remove the pressure regulator.
4. Install in the reverse order of removal.
Tightening torque:
8—11 Nm (0.8—1.1 m-kg, 69—95 in-lb)
Pulsation Damper
1. Remove the delivery pipe assembly. (Refer to page
4C-63.)
2. Remove the pulsation damper.
3. Install in the reverse order of removal.
Tightening torque:
25—34 N m (2.5—3.5 m-kg, 18—25 ft-lb)
Fuel Filter
Low pressure side (In-tank filter)
Refer to page 4C—60.
76G04C-124
High pressure side
The fuel filter must be replaced at the intervals out-
lined in the maintenance schedule.
Warning
Always work away from sparks or open
flames.
1. Disconnect the fuel hoses from the fuel filter.
2. Remove the fuel filter and the bracket.
3. Install a new filter and the bracket.
4. Connect the fuel hoses.
Note
When installing the filter, push the fuel hoses
fully onto the fuel filter and secure them with
spring clamps.
4C-64

EGR SYSTEM (UNLEADED FUEL) 4C
Apply 12V
J* Port
76G04C-147
86U04A-133
76G04C-148
4. Disconnect the solenoid valve connector.
5. Connect 12V and a ground to the terminals of the
solenoid valve.
6. Blow through the solenoid valve from vacuum hose
A.
7. Check that air flows from the air filter.
EGR Modulator Valve
1. Remove the EGR modulator valve.
2. Plug the No. 1 port and connect a vacuum pump
to the No. 3 port.
3. Blow into the exhaust gas port. Operate the vacu-
um pump and verify that vacuum is held.
4. Release the exhaust gas port and confirm that
vacuum is released.
EGR Control Valve
1. Warm up the engine and run at idle.
2. Disconnect the vacuum hose from the EGR con-
trol valve and plug it.
3. Verify that the engine runs smoothly.
4. If not correct, clean the exhaust gas passage in
the valve or replace the valve.
Note
Before replacing the EGR control valve, check
the intake air and control systems.
5. Connect a vacuum pump to the valve and apply
vacuum.
6. Verify that the engine runs roughly or stalls at more
than the specified vacuum.
Specification:
40—60 mmHg (1.6—2.4 inHg)
7. If not correct, replace the EGR control valve.
76G04C-149
4C-79

4C EEC SYSTEM
Solenoid Valve
1. Remove the solenoid valve.
76G04C-159
2. Connect vacuum hoses to the valve as shown in
the figure.
3. Blow air through the valve from hose A and check
that air comes out of the valve air filter.
4. Apply 12V and ground the solenoid valve with jum-
per wires.
5. Blow air through the valve from hose A and check
that the air comes out of port B.
6. Replace, if necessary.
86U04A-151
Two-way check valve
Inspection
1. Remove the two-way check valve.
76G04C-160
4C-84
Connect a pressure gauge to the passage that nor-
mally is connected to the fuel tank.
Blow through the valve from port A. Verify that the
valve opens at 2.94 kPa (0.03 kg/cm2,0.43 psi).
Remove the pressure gauge and connect
it
to the
passage to atmosphere.
Blow through the valve from port B. Verify that the
valve opens at 0.98 kPa (0.01 kg/cm2,0.14 psi).

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

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

4D ON-VEHICLE MAINTENANCE
ON-VEHICLE MAINTENANCE
76G04D-004
AIR CLEANER ELEMENT
Check the air cleaner element for excessive dirt, dam-
age, or oil. Replace if necessary.
Caution
(Wet type)
Do not clean the air cleaner element with com-
pressed air, replace if necessary.
(Dry type)
When cleaning the air cleaner element, blow
dust off from the inside first, then blow off the
outside.
(General)
1. Loosen the drain plug of the sedimenter and let
the water drain. If necessary loosen the air bleed-
ing plug.
2. Bleed air from the sedimenter.
AIR BLEEDING
From Fuel Tank to Fuel Filter
1. Loosen the air bleeding plug of the fuel filter.
2. Pump the priming pump until no air bubbles flow
from the air bleeding plug hole.
3. Depress the priming pump and tighten the air
bleeding plug.
Note
Open only the air bleeding plug of the filter.
From Fuel Filter to Injection Pump
Pump the priming pump until it becomes hard to
pump.
76G04D-007
WATER DRAINING
(ECE)
1. Loosen the drain plug of the fuel filter.
2. Pump the priming pump.
3. Bleed air from the fuel filter.
4D—4