1990 MAZDA 232 Workshop Manual Suplement

Fl INDEX
1. Fuel tank
Removal I hspection /
I nstalIation
1. . . . . . . . . . . . . . * . . . ..I..... ,*,.
page Fl-10
2. 4x4 control unit (Fuel pump control unit)
Inspection .__...._..................__..._. page Fl-12
Replacement _. . _. _. _. _. . _ _ _. . . _ . _. _. . . . _.
page
Fl - 12
3. Transfer pump switch
Removal / lnstaltation . . . . . . . . . . . . . .._ page Fl-13
inspection .._......_.. . . ..-_. . . .._....... page F1 -I 3 93GOFl-702
4. Transfer pump
inspection _........._....._................ page Fl-13
Replacement.. . .__.-.. . . . . . . . . . . . . . . , U.-e
page
FI -13
5. Exhaust system components
Removat I hspection I
Installation
.**...**..a*..........*..*..__.
page fl-15
Fl-2

OUTLINE Fl
OlJTLlNE OF CONSTRUCTION
The fuel and emission control systems of the New 3.23 BP SOHC-engine equipped 4WD model are basically
the same as those of the New 323 8P DOHC-engine equipped 2WD model, however, the fuel tank is designed
with separate right
and left sections due to the installation of the propeller shaft for the 4-wheel-drive system
and
a transfer pump is equipped to pump the fuel from the left to the right (fuei pump side) section of the
fue! tank. The following chart shows the differences between the major parts of the BP DO% 2WD model
and the BP SOHC 4WD model.
33GO”l-703
Difference
I t
Part BP DOHC 2WD 1 BP SOHC 4WD Remark Transfer pump -
0 Due to
installation of propeller shaft
Variable Inertra charging system 0 -
Two group fuel qectron Due to change of engine
-
G-slgnal (Drstnbutor) 0
I -
Due to abolishment of two group fuel Injection
93GOfl-70s
SPECIFICATIONS
Item
Idle speed
Ignition timing * Engine
vm
BTDC BP SOHC
850 * 50
5 * to
Fuel DUtTlD I
Fuel filter
Type Low-pressure side
Htgh-pressure side Nylon element
Paper element
Pressure regulator
Regulating pressure kPa (kglcm2, psi) 1 264-314 (2.7-3.2, 38.3-45.5)
In
jfXt0r
Type
Resistance High-ohmic
12-16
Idbup solenoid vatve
Resistance Solenoid A _.._. 17-23, Solenoid 5, C ._... 27-36
Water themosensor
R&stance -20% ( -4OF)
kQ - . 20°C ( 689=)
40% (104OFj
80°C (176OF) 14.6-l 7.8
2.2-I -2.69
1.0-l -3
0.29-0.35
l TEN terminal of dragnosrs connector grounded.
The a (shading) rndrcates newly equipped parts

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

-- -
“-
I t-
SQLENOlD VALVE AEAR WINOOW
(PRESSURE IQNITION HEADLIG t IT
DEFFIOSTER
REGULATOR SWITCH SWITCH
SWITCH
CONTROL)
lNJECTOR ELECTRICAL
MAIN RELAY , FAN
AX SWITCH
r DliiGNOSlS BLOWER Ivc
CONNECTOR SWITCH RELAY
ECU
AIRFLOW METER
Tt
WATE!
THERMOSENSOR
CLUTCH [/ t
-I
’ NEUTRAL
SWITCH SWITCH 4X4 CONTROL UNIT
1
FbEL
PUMP
TRANSFER PUMP TRANSFER
PUMP SWlTCtJ

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).
Fl-6

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.
Fl-7

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.
Fl-8

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.
Fl-9