1987 MAZDA 626 fuel

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

4D SUPERCHARGING SYSTEM (RF-CX)
ON-VEHICLE INSPECTION
Boost Pressure
1. Connect a pressure gauge to the hose from the
intake manifold.
2. (On chassis dynomometer, full load)
(1) Set the vehicle on a chassis dynomometer.
(2) Run the vehicle in gear at 3,000 rpm with the
acceleration pedal fully depressed.
(3) Measure the boost pressure.
Boost pressure:
82 kPa (0.87 kg/cm2, 8.1 psi)
Note
The above inspection should be done on a
chassis dynomometer. If a dynomometer is
not available follow the below procedure.
3. (Off chassis dynomometer, no load)
(1) Shift the transaxle out off gear.
(2) Run the engine in neutral at 3,000 rpm of the
engine no load.
Measure the boost pressure.
Boost pressure:
5 kPa (0.05 kg/cm2, 0.7 psi)
Note
The boost pressure is varied by engine speed
and engine load.
(3) Remove the starting valve bypass hose.
(4) Check that the bypass valve is closed at 3,000
rpm.
4.
If
the pressure is below specification, check the fol-
lowing. Replace the Comprex supercharger if
necessary.
(1) Intake air and exhaust passages leakage
(2) Intake air and exhaust passages clogged
(3) Wastegate (Refer to 4D—12.)
(4) Starting valve (Refer to 4D—15.)
(5) Fuel system (Injection nozzle... refer to page
4D—31, injection pump...refer to page 4D—24,
etc.)
5. If the pressure exceeds specification, check the
wastegate operation. (Refer to page 4D—12.)
4D—11

FUEL SYSTEM 4D
FUEL SYSTEM
STRUCTURAL VIEW
RF-CX
RF-N
76G04D-046
1. Fuel tank
2. Fuel filter
3. Fuel injection pump
4. Fuel injection nozzle
5. Sedimenter
4D—21

4D FUEL SYSTEM
76G04D-047
76G04D-048
76G04D-049
FUEL FILTER
On-Vehicle Inspection
Check for water in the fuel filter. If present drain the
water. (Refer to page 4D—4.)
Replacement
Removal
1. Disconnect the water level sensor connector (ECE).
2. Remove the water level sensor. (ECE).
3. Remove the fuel filter cartridge.
Warning
Keep fire and open flame away from the fuel
area.
Installation
1. Apply fuel to the O-ring of the fuel filter cartridge
and install it onto the filter body.
2. Install the water level sensor (ECE).
3. Connect the water level sensor connector (ECE).
4. Bleed air from fuel filter. (Refer to page 4D—4.)
5. Check for fuel leakage.
SEDIMENTER (GENERAL)
On-Vehicle Inspection
Check for water in the sedimenter. If present, drain
the water. (Refer to page 4D—4.)
4D—22

FUEL SYSTEM 4D
Replacement
1. Remove the sedimenter from the body.
2. Apply fuel to a new O-ring, and install it onto the
sedimenter body with water level sensor.
76G04D-051
WATER LEVEL SENSOR
Inspection
1. Remove the water level sensor.
(ECE)
Remove the water level sensor from the fuel filter.
(GENERAL)
Remove the water level sensor from the sedimenter
body.
76G04D-052
2. Check the water level sensor for continuity with an
ohmmeter. Replace if necessary.
ECE
Continuity : Pulled condition
No continuity: Pushed condition
76G04D-053
GENERAL
Continuity : Pushed condition
No continuity: Pulled condition
3. Apply fuel to a new O-ring and install it onto the
sensor.
4. Install the water level sensor to the fuel filter (ECE)
or the sedimenter (General).
5. Check for fuel leakage.
76G04D-054
4D-23