1990 MAZDA 232 fuel

I
(WITH INTAKE AIR
THERMOSENSOR) AIR CLEANER METER
RESONANCE
CHAMBER /
SOLENOID VALVE
(PRESSURE REGULATOR CONTROL) FUEL FILTER
(HIGH-PRESSURE
SIDE)
P-“---j
Ne-S’GtiAL * ----El
DlSTRlfjUTOR IDLE-UP
SOLENOID VALVE
* TO ENGINE CONTROL UNIT ,CHECKVALVE
(TWO-WAY)
FUEL VAPOR VALVE
*
THERMOSENSOR
‘FUEL PUMP
FUEL FILTER
I TRANSFER PUMP

Fl FUEL SYSTEM
FUEL SYSTEM
OUTLlNE
PRESSURE REGULATOR
1
FUEL FILTER
I TRANSFER PUMP
i WEL PUMP
1 FILTEF
FUEL TANK
4x4 CONTROL UNIT (FUEL PUMP CONTROL UNIT)
The fuel system consists of the fuel tank, the transfer pump, the fuel pump, the fuel filters, the pressure regu-
lator, the delivery pipe, the injectors, and the 4x4 control unit (fuel pump control unit).
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c
I
FUEL SYSTEM Fl
FUEL TANK AND TRANSFER PUMP
TRANSFER PUMP SWITCH
4x4 CONTkOL UNIT
(FUEL PUMP CONTROL UNIT)
93GOF1-717
The fuel tank is designed with a separate right and left section due to the installation of the propeller shaft
for the 4-wheel-drive system.
A transfer pump is used to pump the fuel from the I& to the right (fuel pump) side. The transfer.pump is
installed in the fuel tank, and is controlled by the transfer pump switch and the fuel pump contra! unit (Includ-
ed in the 4x4 control unit).
A fuel vapor valve is instatted on the top of the fuet tank to prevent fuel from flowing out to the charcoal cansiter.
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Fl FUEL SYSTEM
Transfer Pump Csntrol
OutIine
The fuel tank is built with separate right and left sections to accommodate the installation of the propeller
shaft. As fuel is pulled from the right side of the tank, the transfer pump pumps the fuel from the left to the
riuhf (fuel pump) side to balance the fuel level.
FUEL IN 1EFT TANK
4x4 CONTROL UNIT
(FUEL PUMP CONTROL
UNIT)
TRANSFER / TRANSFER PUMP
PUMP SWITCH: OFF
NO FUEL IN LEFT TANK
4x4 CONTROL UNIT
(FUEL PUMP CONTROL
UNIT) / TRAtdFER PUMP
TRANSFER PUMP SWITCH: ON
Fuel in left tank
The transfer pump switch is OFF, and the transistor within the fuel pump control unit is ON.
As a result, current flows to the coil, the switch is switched ON, and the transfer pump is activated.
No fuel in left tank
The transfer pump switch is ON, and the transistor within the fuel pump control unit is OFF.
As a result, the current to the coil is interrupted, the switch
is switched OFF, and the transfer pump is stopped.
When in this condition, if the vehicle were driven on a rough road surface, the fuel level would vary up and
down and fuel pump would switch ON and OFF.
The transfer pump would then operate excessively, shortening the pump life. In order to prevent this, a ten-
second delay circuit is provided within the fuel pump control unit.
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SUPPLEMENTAL SERVICE INFORMATION, FUEL SYSTEM Fl
SUPPLEMENTAL SERVICE INFORMATION
The following points in this section are changed in comparison with Mazda 323 Workshop Manuals
(I 203-I U-89F, 1204-I O-89F, I2061 O-89F).
fuel tank
l Removal I Inspection I Installation
4x4 control unit (Fuel pump control unit)
l Inspection procedure added
l Replacement procedure added
Transfer pump switch
l Inspection procedure added
l Replacement procedure added
Transfer pump
l Inspection procedure added
l Replacement procedure added
Exhaust system components
l Removai I Inspection I installation 93GOF? -706
FUELSYSTEM
PRECAUTION
Fuel Pressure Release and Sewicing Fuel System
Fuel in the fuel system remains under high pressure when the
engine is not running.
a) Before disconnecting any fuel line, release the fuel
pres-
sure from the fuel system to reduce the possibility of injury
or fire.
1. Start the engine.
2. Push the rear seat cushion buttons and remove the
cushion.
3. Disconnect the fuel pump connector.
4. After the engine stalls, turn off the ignition switch.
5. Reconnect the fuel pump connector and install the rear
seat cushion.
b) Use a rag as protection from fuel spray when disconnect-
ing the hoses.
Plug the hoses after removal.
c> When inspecting the fuel system, use a suitable fuel pres-
sure gauge.
Caution
l Install hose clamps to secure tile fuel pressure
gauge to the fuel filter and the fuel main hose to pre-
vent fuel leakage.
Priming Fuel System
After releasing the fuel pressure for repairs or inspection, the
system must be primed to avoid excessive cranking when first
starting the engine. Follow the
steps below.
I. Connect the diagnosis connector terminals F/P and GND
with a jumper wire.
2. Turn the ignition switch ON for approx. IO sec. and check
for fuel leaks.
3. Turn the ignition switch OFF and remove the jumper wire.
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Fl FUEL. SYSTEM
FUEL TANK
Removal / inspection I Installation
Warning
l Before performing the following operation, release the fuel pressure from the fuel system to
reduce the possibiIity of injury or fire. (Refer to page Fl-9.)
l When removing the fuel tank, keep sparks, cigarettes, and open flames away from it.
l Before repairing the fuel tank, clean it throughly with steam to remove all explosive gas.
1. Remove in the order shown in the figure.
2. Inspect the fuel tank components visually and repair or replace as necessary.
3. Install in the reverse order of removal, referring to Installation Note.
FUEL PUMP (MAIN) TRANSFERPU
4341 (4.4-6.2, 3245)
GASKET, REPLACE
ET, REPLACE
4it-55 (4.3 -5.6, 3041)
Nm (m-kg, ft-lb)
a?cnc% .7*7

FUEL SYSTEM, TRANSFER PUMP CONTROL SYSTEM Fl
Note
l Drain the fuel from the fuel tank before removing the tank.
I. Fuel pump cover
2.
Fuel pump connector
3. Fuel hoses
Installation
Note . . . . . . . . . . . . , . . . . . . . . . . . . . . _ . . . . . below
4. Exhaust pipe
Removal / lnstaltatjon . . . . . . . . . . . . .._. page Fl -I 5
5. Propeller shaft
Removal / installation ._..._....,_.._..._.. Section L 6. Fuel fiIler hose, breather hose, and
evaporation
hoses
Installation Note . . . ..*..**......*........~_.....~.
below
7. Fuel tank straps
8. Fuel tank
inspect for cracks and corrosion
93m=: -708
I B FUEL FILLER HOSE
22%
-.
-L
0 F /
@,
M
E -J
03UOFX-Bf 4
93GOFl-709
Installation Note
1. Push the ends of the main fuel hose, fuel return
hose, and
evaporative hoses onto the fuel tank fittings at least 25mm
(1.0 in).
2. Push the fuel filler hose onto the fuel tank pipe
and filler pipe
at ieast 35mm (1.4 in).
TRANSFER PUMP CONTROL SYSTEM
SYSTEM OPERATION ’
1. Turn the ignition switch ON and verify that the fuel
gauge
indicates more than half and that the transfer pump oper-
ating sound is heard.
Warning
l If the fuel level is less than one half, this inspec-
tion cannot be performed.
2. Ground the transfer pump connector terminal-wire (Y/L) with
a jumper wire and verify that the transfer pump stops.
3. Remove the jumper wire and verify that the transfer pump
begins operation after approx. 50 sec.
4. If not as specified, check the following parts.
l 4x4 control unit (Fuel pump control unit).
(Refer to page F-I-1 2.)
l Transfer pump. (Refer to page FI-I 3.)
l Transfer pump switch. (Refer to page Ff -13.)

Fl TRANSFER PUMP CONTROL SYSTEM
93GOFl-7 10
93GOF1-717
93GOf t -7 I
4x4 CONTROL UNIT (FUEL PUMP CONTROL UNIT)
Inspection
I. Remove the 4x4 control unit.
2. Disconnect the 4x4 control unit connector.
3. Check continuity between the 4x4 control unit connector
terminal M and a ground.
4. Perform the following inspection according to the measured
continuity.
Continuity exists
1. Turn the ignition switch ON.
2. Ground the 4x4 control unit terminal M with a jumper wire
and verify that the voltage at the 4x4 control unit terminal
N is ov.
3. Remove the jumper wire and verify that the voltage at the
4x4 control unit terminal N is approx. WV after approx.
10 sec.
4. If not as specified, replace 4x4 control unit.
No continuity exists
1, Turn the ignition switch ON and verify that the voltage at
the 4x4 control unit terminal N is OV.
2. Disconnect the transfer pump connector.
3. Turn the ignition switch ON and verify that the voltage at
the 4x4 control unit terminal N is approx. WV.
4. If not as specified, replace 4x4 control unit.
Replacement
I. Remove the bolts and remove the 4x4 control unit and the
bracket as an assembly.
2. Remove the 4x4 control unit from the bracket.
3. Install in the reverse order of removal.
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