fuel MAZDA 232 1990 Suplement Repair Manual

I
F2
fNSPECTlON ACTION
I Check if cootrng system IS OK’
YES Go to next step
No Repair or reptace
l Thermostat l
l Electric cooling fan * l Radiator*
5 Try known good ECU and check if condltlon Yes Replace ECU * rnproves
NO Change fuel to another brand or use
higher octane fuel
l Refer to 323 Workshop Manual [1203-l O-89F (Europe) or It 204-I O-89F (Australia)]. %%‘3OF2-748 -
F2-4 I

F2 FUEL SYSTEM
FUEL
SYSTEM
PREPARATlON
SST
49 LO18 901
Injector checker For
lnsgectlon of
injector
93GOF2.770
9MUOF2-722
03UOFX-7 27
F2-50
PRECAUTION
Fuel Pressure
Release and Servicing 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 fife,
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 stalts, turn off the ignition switch.
5. Recpnnect 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 the fuel pressure
gauge to the fuel filter and the fuel main hose to pre-
vent fuet 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.
1. Connect the diagnosis connector terminals F/P and GND
with a jumper wire.
2. Turn the ignition switch
ON for approx. 10 set, and check
for fuel leaks.
3. Turn the ignition switch OFF and remove the jumper wire.

FUEL SYSTEM F2
FUEL TANK
Removal I inspection / Instatlation
Warning
l Before performing the following operation, release the fue1 pressure from the fuet system to
reduce the possibitity of injury or fire. (Refer to page F2-50.)
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 and repair or replace as necessary.
3. tnstall in the reverse order of removal, referring to Installation Note.
FUEL PUMP TRANSFER PUMP
0 SEAL RUBBER, REPLACE 7
A SSL
40-55 (4.1-56, 30-41)
N-m {m-kg, Mb)
93GOF2-771
F2-51

F2 FUELSYSTEM
Note
l Drain the fuei from the fuel tank before removing the tank.
1. Fuel pump cover
2. FueI pump connector
3. Fuel hoses
Installation Note ..___........_.....__......_...._. below
4. Exhaust pipe
Removal / installation . . . . . . . .__._. . , . . . FZ-57, 58
5. Propeller shaft
Removal ! Installation .._._...._....._.._.. Section L 6. Fuel filier hose, breather hose, and
evaporation hoses
tnstal!ation Note ..m..,* . . . . ...*-. *..,- . . . . m...-e.. below
7. Fuel tank straps
8. Fuel tank
Inspect for cracks and corrosion
93GOF2-772
0 FUEL FILLER HOSE
03UOFX- 13! installation Nate
1. Push the ends of the main fuel hose, fuel return hose, and
evaporative hoses onto the fuel tank fittings at least 25mm
(1 .O in).
2. Push the fuel filler hose onto the fuel tank pipe and filler pipe
at least 35mm (1.4 in).
TRANSFER PUMP CONTROL SYSTEM
System Operation
I. 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 terminai-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. IO sec.
4. If not as specified, check the following parts.
l Fuel pump control unit. [BP turboJ
(Refer to page F2-53.)
4x4 control unit [BP SOHC] (Refer to page Fl-12.)
l Transfer pump. (Refer to page F2-54.)
. Transfer pump switch. (Refer to page F2-54.)
93GOF2-774
F2-52

FUELSYSTEM F2
FUEL PUMP CONTROL UNIT
I I 93GOF2-775
1
93GOF2-799
I 93GOF2-800
I 93GOF2.776
FUEL PUMP CONTROL UNIT [BP TURBO] l
Refer to page Fl-12 for BP SOHC model.
hspection
1. Remove the fuel pump control unit.
2.
Disconnect the fuet pump controt unit connector.
3. Check ctintinuity between the fuel pump control unit con-
nector terminal B (Y/L) and a ground.
4. Perform the following inspection according to the results of
the continuity check.
Continuity exists
1. Turn the ignition switch ON.
2. Ground the fuel pump control unit terminal B (Y/L) with a
jumper wire and verify that the voltage at the fuel pump con-
trol unit terminal D (in’) is OV.
3. Remove the jumper wire and verify that the voltage at the
fuel pump control unit terminal D (L/Y) is approx. WV af-
ter approx. IO sec.
No continuity exists
1. Turn the ignition switch ON
and verify that the voltage at
the fuel pump control unit terminal D (L/Y) is OV.
2. Disconnect the transfer pump connector.
3. Turn the ignition switch ON and verify that the voltage at
the fuel pump control unit terminat D (LA’) is approx. t2V.
Replacement
1. Move the driver’s seat backward.
2.
Remove the bolts and remove the fuel pump control unit
and bracket as an assembly.
3. Remove the fuel pump control
unit from the bracket.
4. Install in the reverse
order of removal.
F2--53

F2 FUELSYSTEM -.
03UOFX-82: 93GOF2-777
2
r
TRANSFER PUMP SWlTCH
Removal I Installation
1. Refer to replacement of the transfer pump.
(Refer to below.)
Inspection
1. Check continuity between transfer pump connector termi-
nal C and ground terminal.
r Float Dosition I Comnuity
I
I Down I Yes
I
2. If not as specified, reptace the transfer pump switch.
TRANSFER PUMP
Inspection
1. Remove the rear seat cushion.
03UOFX-823 2. Disconnect the transfer pump connector.
3. Check for continuity between transfer pump connector
terminal-wires (ES) and (t/V).
4. If no continuity exists, replace the transfer pump.
03UOFX-825
F2-54
Replacement
Warning
l When servicing the fuel system, keep sparks,
cigarettes, and open flames away from the fuel.
1. Remove the rear seat cushion.

FUEL SYSTEM F2
2. Remove the service hole cover of the transfer pump.
3. Disconnect the transfer pump connectors.
4. Disconnect the fuel hose,
5.
Remove the transfer pump.
6. Install in the reverse order of removal. Caution
l Install a new seat rubber.
03UOFX-826
Disassembly I Assembly
Caution
l Prevent contaminants from entering the transfer pump.
1. Disassemble in the order shown in ,the figure.
2. Assemble in the reverse order of disassembly.
3. Verify that the transfer pump operates correctly after assembling it.
HOSE, REPLACE
@
1. Fuel filter
2. Rubber mount
3. Transfer pump 4. Fuel hose
5. Transter pump switch assembly
93GOF2-77:
FZ-55

F2 FUEL SYSTEM
93GOF2-775
1 93GOF2-78(
93GOF2-78:
1
93GOF2-78;
-
93GOF2-783
FUEL PUMP RESISTOR/RELAY
System Operation
I. Remove the rear seat cushion.
2,
Measure the voltage at the fuel pump connector terminal
A {G/O).
Voltage
r Crankinq Approx. 12V
I
I- Others t ACKXOX. I OV i
3. If not within specification, perform the following inspection,
and repair or replace if necessary.
l Fuel pump resistor/relay resistance. (Refer to below.)
l ECU II terminal voltage. (Refer to page F2-60.)
l Wiring harness and connector.
inspection
1.. Disconnect the connector.
2. Ground the fuel pump resister relay terminal D.
3. Apply 12V to terminal C and check for continuity between
terminals A and B.
Terminal C
12 applied
ov Continutty between A and B
NO
Yes
4. Measure the resistance between terminals E and F.
Resistance : 0.62-0.66Q [at 20% (68OF)l
INJECTOR
Volume Test
1. Remove the injectors with the delivery pipe.
2. Affix the injectors to the delivery pipe with wire.
Caution
l Affix the injectors firmly to the delivery pipe so that
no movement of the-injectors is possible.
Warning
l Be extremely careful when working with fuel.
Always work away from sparks or open flames.
3. Connect the SST to the battery and injector.
4. Check the injection volume with a graduated container.
Injection volume:
BP SUHC....44-47 cc (2.68-2.87 cu in)/15 sec.
BP Turbo
. ...87-105 cc (5.31 -6.41 cu in)/15 sec.
Caution
l When using the SST, make sure of the SST num-
ber and use correct one.
5. If nut correct, replace the injector(s).

F2 CONTROL SYSTEM
Terminal voltage [BP TURBO]
eminal input Output , 1 Connected to Test condition Correct voltage Remark
IA - - Battery Constant Approx. 12V for backup
15 0 Main relay OFF Approx. OV
(FUEL INJ relay) tgnltlon switch
-
ON Approx. 12V
1c 0 1 Ignition switch Wniie cranking Approx. 1 OV
-
(START)
lgnrtron switch ON Approx. OV
ID 0 Self -Diagnosis Test switch at “SELF-TEST” With Self-
Checker Lamp illuminated ior 3 sec. after ignition Approx. 5V Diagnosis Check-
(Monitor lamp) switch OFF* ON er and System
Lamp not illuminated after 3 sec. Approx. 12V Se’ector
Test switch at
“02 MONITOR” at idle
Monitor lamp illuminated Approx. 5V
Test switch at
“02 MONITOR” at idle
Monitor lamp not illumrnated Approx. 12’4
-lE - - - -
- -
1F 0 Self-Diagnosis Buzzer sounded for 3 sec. after ignition
Below 2.5V l With Self-
Checker switch OFF -+ ON Diagnosis
(Code Number)
Buzzer not sounded after 3 sec. Approx. 12V Checker and
Buzzer sounded Below 2.9 System Selector
l With System
Buzzer not sounded Approx. 12V Selector test
switch at
“SELF-TEST’ ’
I I 1G
0 Igniter
7H
0 Solenoid vahe
(Wastegate)
l!
0 Fuel pump
resistor/relay
I
lJ I r-Tcreiay Ignition switch ON
ld!e
Engine speed below 5,300 rpm
Engine speed above 5,300 rpm
While cranking
Idle
Ignition switch ON
AK switch ON at idle 1 Approx. OV
-
Approx. 0.2V
Approx. 12V
-
Below 1.5V
Approx. 1 OV
-
I3elow 15V
Approx. 12V
Below 2.5V
AIC switch OFF at idle Approx. 12V
-
IK 0 Diagnosis System Selector test switch at
connector
(TEN terminal)
1L - - -
- -
-
IM
t 0
1 Ground (Australia) Constant Below 1 .OV Not used
(Except Australia)
F2-60

CONTROL SYSTEM F2
Incorrect voltage Possible cause
Always OV
l ROOM 10A fuse burned l Open circuit in wiring from ROOM 10A fuse to ECU termrnal IA
Always OV
I l Main relay maifunctlon l Open or short crrcu~t in wirrng from main relay to ECU termrnal 1 B
Always OV (Srarrer turns)
l Open or short circuit in wiring from ignition switch to ECU terminal 1C
Always UV
l Main relay (FUEL INJ relay} malfunctron l Open circuit in wiring from main relay to diagnosis connector terminal + B l Open or short circuit in wiring from dragnosls connector terminal MEN to
ECU terminal 1D
Always approx. 12V
I . Poor connection at ECU connector
l ECU matfunction
Always approx. 5V
l ECU malfunction
-
I -
Always below No disptay on Self- . Main relay (FUEL INJ retay) malfunction (Refer to page F3-142)
2.5V Diagnosis Checker l Open circuit in wiring from main relay to diagnosis connector termjnal + B
“88” displayed and
l Open or short circuit in wiring from diagnosis connector terminal FEN to
buzzer sounds con- ECU terminal 1 F
tinuously
Always approx. 12V
l Poor connection at ECU connector l ECU malfunction
Always OV
l Short circuit in wiring from igniter to ECU terminal tG
Atways OV or approx. 12V
l Refer to Code No.42 Troubleshooting (Refer to page F2-30)
Always approx. 12V
l Fuel pump resistor/relay malfunction
Always OV
l Open or short circuit in wiring from ECU terminal 1 I to resistor/retay
Always below
A/C does not operate
l AJC relay malfunction
23 l Open circuit in wiring from ignition switch to NC relay l Open circuit in wiring from A/C relay to ECU terminal IJ
A/C switch OFF but
l Short circuit in wiring from A/C relay to ECU terminal IJ
AIC operates
l ECU matfunction
Always approx. t2V
Always below 1 .OV
l Poor connection at ECU connector l ECU malfunction
l Short circurt in wiring from diagnosis connector terminal TEN to ECU termi-
nal 1K
Always approx. 12V
l Open circutt in wiring from diagnosis connector terminal TEN to ECU termi-
nal lK
l Open c~rcud in wiring from diagnosis connector terminal GND to ground
Always above 1 .OV
I
l Open circuit in wiring from ECU terminal 1 M to ground
F2-61