1990 MAZDA 232 fuel

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

F2 TROUBLESHOUTING GUIDE
I 22 KNOCKtNG [8P TURBO] I
IESCW-
l Abnormal combustron accompanied by audible “pinging” noise rim
TROUBLESHOOTING HtNTS]
3 incorrect ignition timing (Too advanced) @ Low octan fuel used
2
Knock control system malfunction @ Air/Fuel mixture lean
3 Carbon deposits in cylinder l Fuel injection amount not correct
3 Overheating l Fuel line pressure decreases while accelerating
TEP INSPECTION ACTlON
1
Connect System Selector to diagnosis connector Yes Go to next step
and set Test Switch to “SELF TEST” and check
for correct ignition timing at idle after warm-up’
ignition timing: BTDC 10 f lo
No Adjust
2 Check if “00” is displayed on Self-Diagnosis Yes Go to next step
Checker with igmtlon switch UN*
No Matf unction Code No. displayed
Check for cause (Refer to specified
check sequence) *
“88” flashes
Check ECU terminal 1 F voltage
Vottage: Approx. 12V
(Ignition switch ON) 0 page FZ-60
4 If OK, replace ECU
W: SELF TEST
4 If not OK, check wiring between
ECU and Self-Diagnosis Checker
3 Check for correct fuel line pressure at idle* Yes Check if fuel Iine pressure decreases
when accelerating quickly
Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm2, 38-46 psi)
(vacuum hose to pressure regulator dis-
connected) 4 If decreases, check for clogging
between fuel pump and pressure
regulator
e If no decrease, go to next step
No tow pressure Check
fuel line pressure while pinching
fuel return hose
3 If fuel line pressure quickly in-
creases, check pressure
regulator*
4 If fuel line pressure gradually in-
creases, check for clogging be-
tween fuel pump and
pressure
regutator
If not clogged, check fuel pump
maximum pressure*
- -
.-
Refer to 323 Workshop Manual [1203-IO-89f (Europe} or t204-IO-89f (Australia)]. F2-40

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.