1990 MAZDA 232 ignition

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

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

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.
Fl-12

F2 TURBOCHARGER CONTROL [BP TURBO]
93GOF.Z721
!=2-14 LARGE
+ FULLY OPEN
BYPASS AIR
i 8EGlNNIp
AMOLIN OF OPEN
SMALIL
430 VACUUM
(5-l) mmt-lg
TURBOCHARGER OnW
INLET
lntercooler
The air-to-air intercooler utilizes fresh air flow through the in-
tercooler core to reduce the intake air temperature.
If
the air compressed by the turbocharger was sent directly
into the combustion chamber without passing through the in-
tercooler, the charging air efficiency would be
reduced by the
high temperature of the intake aii-.
The intercooler, by cooling this high temperature air, substan-
tially increases the charging air efficiency
and engine output,
as well as supressing ignition knocking by reducing the com-
bustion gas temperature.
The intercooler is mounted at
the left front of the vehicle.
Air Bypass Valve
The air bypass valve bypasses intake air from the air funnel
to before the turbocharger in order to reduce air vibration noise
during deceleration.
When the throttle valve is closed suddenly during high-rpm
and heavy-load operation, air vibration occurs between the
throttle vatve and the turbocharger as a result of pressuriza-
tion
caused by inertia of the intake air. This system prevents
such noise.

F2 FUEL SYSTEM
93GOF2-726
FUEL PUMP RESISTOR/RELAY [BP TURBO]
The fuel pump resistorlretay supplies battery voltage to the
fuel pump when the ECU 11 circuit is OFF, and approx. 1 OV
when the ECU 11 circuit is ON. It is mounted on the firewall.
TRANSFER PUMP CONTROL
Outline
The fuel tank is buitt with separate right and left sections to accommodate the. installation of the propeller
shaft. As fuel is puited from the right side of the tank, the transfer pump pumps the fuel from the left to the
right (fuel pumb) side to balance the fuel level.
FUEL IN LEFT TANK
I
FUEL PUMP CONTROL. UNIT
/ TRANSFER PUMP
TRANSFER PUMP SWITCH: OFF
NO FUEL IN LEFT
TANK
FUEL PUMP CONTROL UNIT / TRiNSFER PUMP
TRANSFER PUMP SWITCH: UN
93GOF2-727
Operation 1. Whenever the ignition switch is ON and fuel is in the left (transfer pump)
side of the fuel tank the fuel pump switch is open, the transfer pump circuit in the fuel pump control unit is
closed, and the transfer pump
operates.
2. When the fuel in the left side of the tank drips betow a specified point, the fuel pump switch is grounded
and the transfer pump stops operation.
3. To prevent the transfer pump from
being turned ON and OFF repeatedly, possibly shorting the life of the
pump, when the vehicle is driven on a rough
road and the fuel level is low, there is a ten-second delay
circuit in the control unit to delay the turning ON and OFF the pump.
f2--I 8

F2 CONTROL SYSTEM
KNOCK CONTROL SYSTEM [BP TURBO]
This svstem retards the ignition timina when enaine knocking occurs because of usage of low octane fuel, etc.
1NTAKE
MANIFO
KNOCK SENSOR
(INSTALLED BETWEEN No.2 AND
No.3 CYLINDER)
IGNITER
KNOCK iX?NTROL
UNIT
Operation
When the engine vibrates, the knock sensor generates a slight voltage signal that is the sent to the knock
control unit. The knock control unit determines whether the signal is a knocking signal. If it is a knocking
signal, the ignition spark is retarded according to the intensity of the knock to a maximum of 4O.
Inhibition of spark retardation
In order to improve drivability and fuel economy, the ECU inhibits the above spark retardation when the
‘engine load Ls light, the coolant temperature is below O°C (32OF), the engine is cranking during engine test
conditions.
Note
l The knock ~ensur and knock control unit cannot be inspected individually.
When a matfunction code number 05 is indicated, replace the knock controt unit or sensor
only after inspecting the related wiring and connectors.
F2-22

F2 CONTROLSYSTEM
AK CUT-OFF SYSTEM (AI-X)
To improve the retiability of the engine at high temperature condition, the water thermoswitch on the radiator
is switched OFF above approx. II I “C (232OF) and stops the A/C operation.
ECU
NC OPERATION BLOWER FAN
WATER
THERMOSWITCH
IABOVE
111 OC (232OF): OFF]
NC SWITCH
IGNITION
T
l 1
BLOWER SWITCH
MAGNET
CLUTCH
93GOF2-73
F2-24