1990 MAZDA 232 engine

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

CONTROL SYSTEM F2
t OXYGEN SENSOR [BP TURBO]
I
CERAMlC HEATER
93GOF2-733
Because the temperature of the exhaust gas is inherently low in turbocharged engines, the BP Turbo model
uses a rapid heating ceramic heater to detect the air/fuel ratio,
PRESSURE REGULATOR CONTROL SYSTEM [BP TURBO]
PRESSURE
REGULATOR
I SOLENOID VALVE
(PRESSURE REGULATOR CONTROL)
FUEL
+ (FROM
DELIVERY PIPE1
II
FUEL INJ I
RELAY
(MAIN REU\Y)
I
II Ir
-__. _ - -’ VACUUM
CT0 DYNAMIC
Ill
CHAMBER)
BATTERY -
c
FUEL
(TO FUEL TANK)
nme*rn -.-a
To prevent percolation of the fuel during hot restart idle, vacuum to the pressure regulator k cut for 180
sec., and the fuel injection pressure is increased to slightly more than 284 kPa (2.90 kg/cm’, 41.2 psi).
Operating condition
l Coolant temperature: Above 90°C (194OF)
l Intake air temperature: Above 58OC (136OF)
g No-load condition
FZ-23

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

SUPPLEMENTAL SERVICE INFORMATION F2
SUPPLEMENTAL SERVICE INFORMATION
The following points in this section are changed in comparison to the Mazda 323 Workshop Manual
[I 203-I U-89F (Europe) or 120410-89F {Australia)].
intake air system components [BP Turbo]
l Removalllnspectionll nstaltation
WASTEGATE [BP Turbo]
l Inspection
WASTEGATE SULENOlD VALVE [BP Turbo]
l Inspection
Turbocharger [BP Turbo]
l Inspection
l Removalllnstaltation
Air bypass valve [BP Turbo]
l Removal/hstallation
l 1 nspection
lntetcoolet [BP Turbo]
l RemovaMnspection/tnstaltation
Fuel tank
l Removal ! Inspection I Installation
Fuel pump control unit [BP Tubto]/4x4 control unit [BP SOHC]
l 1 nspection
l Replacement
Transfer pump switch
l Inspection
l Replacement
Transfer pump
l Inspection
l Replacement
Fuel pump resistor/relay
l System operation
l Inspection
injector [8P Turbo]
l Volume test
Exhaust system components
l Removal / 1 nspection / Installation
Engine control unit (ECU) [BP Turbo]
l Terminal voftage
Oxygen sensor [BP Turbo]
l Inspection
l Replacement
Knock sensor [BP Turbo]
l Replacement 93GOFZ736
F2-25

F2 TROUBLESt=iUUTlNG GUIDE
SYMPTOM TROUBLESHOOTING
Regarding symptom troubleshooting except LACK OF POWER, POOR XCELERATION, KNOCKING, and
HIGH UIL CONSUMPTION, refer to Workshop Manual [I 203-l O-89F (Europe) or 1204-l O-89F (Australia)].
19 LACK OF POWER [BP TIJR801
DESCRIP- *Performance poor under load when throttle valve wide open
TION *Reduced maximum speed
l Idle condition normal
[TROUBLESHOOTING HINTS1
3 Wastegate always open or opens early
3 Turbocharger damage
@ Factors other than engine malfunction
*Clutch sllpping
l Brake dragging
*Low tire pressure
l Incorrect tire size l Overloaded vehicle
@ Low intake air amount
*Throttle valve not open fully
*Clogged intake air system
TEP INSPECTlON
1
Install pressure gauge in intake air pipe and
check boost pressure at engine speed of
4,000
wm
CT page F2-45
Boost pressure:
More than 2.0 kPa (0.02 kglcm2, 0.3
psi)
@ Air/Fuel mixture lean
l Fuel iine pressure decreases l Fuel injection malfunction
@ Poor ignrtjon
@ Low engine compression
@ Alcohol blended fuel used
@ Knock control system malfunction
ACTION
Yes Go to Step 3
NO Check for air leakage and exhaust gas
leakage
4 If OK, go to next step
4 In not OK, repair
2 Check wastegate
Yes Remove intake air pipe from turbo-
f7 page F2-45 charger and check if compressor wheel
rotates smoothly t7 page F2-46
4 If OK, check air cleaner element
and throttle valve
+ If not OK, replace turbocharger
3 Check factors other than engrne Yes
l Clutch slipping Go to next step
1 8rake dragging
’
l Low tire pressure NO Repair or adjust
l Incorrect tire srze
FZ-32

TROUBLESHUOT1NG GUIDE F2
;TEP
14
15
16 Change fuel and check if condjtjon improves INSPECTION
Check if resistance of rgnrtm
coil IS OK’
Resistance (at 20°C [SS*Fj):
Primary coil winding _....-.. Cl.81 -0.99Q
Secondary coil winding.,.. IO-16 kQ ACTION
Yes Go to next step
PRIMARY COIL
WINDING SECONDARY COIL
WIND tNG
Check fur correct engine compressron”
Yes Go to next step
Engine compression:
785 kPa (8.0 kg/cm2, 1 I4 psi)-300’ rpm L 1
No Check engine condition *
l Worn p&ton, piston rings or cylinder
wall
l Defective cylinder head gasket l Distorted cylinder head l Improper valve seating
l Valve sticking in guide
Yes Change fuel to another brand
No
I I Try known good ECU and check if con-
dition imDroves
* Refer to 323 Workshop Manual [ 1203-lo-89F (Europe) or 1204-l O-89F (Australia)l.
93GOF2-74 6
F2-35

F2 TROUBLESHOOTING GUIDE
20 POOR ACCELERATION [BP TURBO]
IESCRIP- . Performance poor while accelerating
rm
l Idle condition normal
[TROUBLESHOOTING HINTS]
3 Wastegate always open or opens early @ Low intake air amount
3 Turbocharger damage
l Throttle valve not open fully
3 Factors other than engine malfunction *Clogged intake air system l
Ciutch slIpping @ Air/Fuel mixture Iean l Brake draggrng l fuel line pressure decreases
l low tire pressure l Fuel Injection malfunction
l Incorrect tire size @ Poor Ignition
. Overloaded vehicle @ Low engine compression
@ Atcohol blended fuel used
TEP INSPECTION ACTION
-l Install pressure gauge
in intake air pipe and I Yes
1 Go to Step 3
check boost pressure at engine speed of 4,000
rpm
w page F2-45
Boost pressure:
More than 2.0 kPa (0.02 kglcm2, 0.3 psi)
No Check for air leakage and exhaust gas
leakage
4 If OK, go to next step
4 If not OK, repair
2 Check wastegate w page F2-45
Yes Remove Intake air pipe from turbo-
charger and check if compressor wheel
rotates smoothly w page F2-46
c3 If OK, check air cleaner element
and throttle valve
4 If not ok, replace turbocharger
3 Check factors
other than engine
Yes Go to next step l Clutch stipprng l 5rake dragging l Low tire pressure
No l Incorrect ttre size Repair or adjust
FZ-36

TROUBLESl-lOOTING GUIDE F2
;TEP 1 INSPECT1ON
ACTION
13 Check if resistance of ignition coil 1s OK*
Yes Go to next step
Resistance (at 20°C iSS*FJ):
Primary coil winding . . . . . . . .
0.81~-0.99Q
Secondary coil winding,,.. 1 O--16 kR
PRIMARY COIL
WINDING SECONDARY COIL
WlNDlNG
NO Replace
14 Check for correct engine compression”
Yes Gc to next step
1 Engine compression (Minimum):
785 kPa (8.0 kg/cm , It4 psi)-300 ipm
NO Check engine condition” l Worn piston, piston rings or cylinder
wall
l Defective cylinder head gasket l Distorted cylinder head l Improper valve seating
*Valve sthing in guide
15 Change fuel and check if acceleration improves
Yes Change fuel to another brand
NO
Go to next step
16 Check if NC cut-off control system is OK’
Yes Go to next step
No Repair or replace
17
I Try known good ECU and check if condition
improves
* Refer to 323 Workshop Manual [1203-IO-89F (Europe) or i204-IO-89F (Australia)].
93GOF2-747
F2-39