1992 MAZDA PROTEGE fuel

22 KNOCKING
DESCRIP- *Abnormal combustion accompanied by audible “pinging” noise
I-ION
[TROUBLESHOOTING HINTS]
3 Incorrect ignition timing (Too advanced)
@ Air/Fuel mixture too lean
3 Carbon deposits in cylinder
*Fuel injection amount not correct
3 Overheating
l Fuel line pressure decreases while accelerating
TEP INSPECTION
ACTION
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
CT page F-79
Ignition timing (BTDC)
l BP DOHC : go-1 1 o l BP SOHC : 4”-6O
’ B6 No
Adjust a page F-79
2 Check if “00” is displayed on Self-Diagnosis
Yes Go to next step
Checker with ignition switch ON
W page F-62
No
Service Code No. displayed
Check for cause (Refer to specified
check sequence) w page F-63
“88” flashes
Check ECU terminal 1F voltage CT page F-150
Specification: Battery voltage
(Ignition switch ON)
c3 If OK, replace ECU w page F-149
W: SELF TEST c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker
3 Check for correct intake manifold vacuum at idle
Yes Go to next step
VaCUUm: More than 450 mmHg (17.7 inHg) No
Check for air leakage of intake air sys-
tem components
4
Check for correct engine compression
Yes Go to next step
w page Bl-10
B2-10
Engine compression (Minimum):
l BP DOHC
883 kPa (9.0 kg/cm’, 128 psi)-300 rpm
l BP SOHC
834 kPa (8.5 kg/cm*, 121 psi)300 rpm
l B6
932 kPa (9.5 kg/cm’, 135 psi)300 rpm No High compression
Check engine condition CI page 81-10
62-l 0 l Carbon deposits
F-71

F TROUBLESHOOTING GUIDE
STEP INSPECTION ACTION
5 Check for correct fuel line pressure at idle Yes Check if fuel line pressure decreases
w page F-129 when accelerating quickly
Fuel line pressure: + If it decreases, check for clogging
265-314 kPa (2.7-3.2 kg/cm’, 36-46 psi) between fuel pump and pressure
(Vacuum hose to pressure regulator dis- regulator
connected) * If not decrease, go to next step
INSTALL CLAMPS No Low pressure
Check fuel line pressure while pinching
fuel return hose
c3 If fuel line pressure quickly in-
creases, check pressure regulator w page F-129
c3 If fuel line pressure gradually in-
creases, check for clogging be-
tween fuel pump and pressure
regulator
If not clogged, check fuel pump
maximum pressure w page F-126
6 Check if cooling system is OK Yes Go to next step
w page E-13
No Repair or replace
l Thermostat w page E-9
l Electric cooling fan w page E-16 l Radiator w page E-6
7 Try known good ECU and check if condition Yes Replace ECU CT page F-149
improves
CT= page F-149 No
Change fuel to another brand or use
higher octane fuel
23lJOFX.0: .-._ ,
F-72

TROUBLESHOOTING GUIDE F
23 FUEL ODOR
DESCRIP-
*Gasoline odor in cabin
TION [TROUBLESHOOTING HINTS]
@ Poor connection or damaged at fuel system or evaporative emission control system
@ Charcoal canister overflow due to evaporative emission control System malfUnCtiOn
Check for cause (Refer to specified Specification: Battery voltage
(Ignltlon switch ON)
c3 If OK, replace ECU r;+ page F-149 c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker
control) with engine running and throttle valve
opened (Neutral switch connector disconnected)
eck if vacuum is felt
s
23UOFX-029
F-73

F TROUBLESHOOTING GUIDE
I 24 I EXHAUST SULFUR SMELL I
DESCRIP-
l Exhaust gas smells abnormally
TION
[TROUBLESHOOTING HINTS]
High sulfur content fuel used
STEP INSPECTION
1
Change fuel to another brand ACTION
03UOFX-039
25 HIGH OIL CONSUMPTION
DESCRIP-
l Oil consumption excessive
TION
[TROUBLESHOOTING HINTS]
@ PCV system malfunction
@ Engine malfunction (Oil working up, working down, or leakage)
iTEP
INSPECTION
1 Check if PCV hose, ventilation hose or their at- Yes Repair or replace
taching nipples are separated, damaged,
clogged, or restricted
w page F-138 No Go to next step
2 Check if air pressure or oil is present at ventila- Yes Go to next step
tion hose ACTION
No Check engine condition w page 81-3
82-3
l Oil leakage
*Worn valve seal
*Worn valve stem
*Worn valve guide
3 Check if vacuum is felt at PCV valve at idle Yes Check engine condition w page 91-3
w page F-138 82-3
*Worn piston ring groove
*Stuck piston rings l
Worn piston or cylinder
No Replace PCV valve
23UOFX-040 /-.
F-74

TROUBLESHOOTING GUIDE F
26 POOR FUEL ECONOMY
DESCRIP-
l Fuel economy unsatisfactory TION
[TROUBLESHOOTING HINTS]
While fuel consumption is drastically increased by city driving, short-run operation, stop and go driving, extended winter
warm-up periods, etc., as opposed to “trip” mileage, an attempt should be made to determine these factors when con-
fronted with “poor mileage” conditions. However, since the operator is not always at fault, the following is offered.
@II Operator depressing accelerator more than usual due to
@ Air/Fuel mixture too rich
low engine power
l Poor ignition *High fuel line pressure
@ Alcohol blended fuel used
*Low intake air amount
l Electronic spark advance control system malfunction @ High vehicle load l Low tire pressure
*Clutch slipping/ATX slipping l Incorrect tire size l Exhaust component restricted l Brake dragging ;TEP
INSPECTION ACTION
1
Check factors other than engine Yes
Go to next step
l Low tire pressure = Section Q 9 Unrecommended tire srze v Section Q l Clutch slipping w Section H l Brake dragging No
0 Section P Repair
l Exhaust component restricted cz= page F-136
2
Check if air hoses are connected correctly - Yes
Go to next step CI page F-109
No
Repair 3
Check if “00” IS displayed on Self-Diagnosis
Yes
Checker with ignition switch ON Go to next step W page F-82 No
SYSTEM SELECT: 1 Service Code No. displayed Check for cause (Refer to specified
check sequence) w page F-63
“88” flashes
Check ECU terminal 1F voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
* If OK, replace ECU CT= page F-149 e If not OK, check wiring between
ECU and Self-Diagnosis Checker 4
Check for correct intake manifold vacuum at idle
Yes Go to next step Vacuum: More than 450 mmHg (17.7 inHg) No
Check for air leakage at intake air sys-
tem components 5
Check if air cleaner element is clean Yes
Go to next step CT= page F-79
No
Replace air cleaner element
F-75

F TROUBLESHOOTING GUIDE
s
-
Ignition timing (BTDC) l BP DOHC : Q”-11 o l BP SOHC : 4O-6“
Fuel line pressure:
216-265 kPa (2.2-2.7 kg/cm*, 31-36 psi)
INSTALL CLAMPS
hose to pressure
ged or poorly con-
c3 If OK, replace pressure regulator w page F-130
c3 If not OK, repair or replace hose
Fuel line pressure: More than 147 kPa
(1.5 kg/cm*, 21 psi) for 5 min.
INSTALL CLAMPS
23UOFX-041
F-76

SELF-DIAGNOSIS FUNCTION F
PREPARATION
SST
49 6019 9AO
System Selector For
diagnosis 49 HO18 9Al
Self-Diagnosis
Checker For
diagnosis
SERVICE CODE NUMBER
Inspection Procedure
1. Connect the SST to the diagnosis connector.
2. Set switch @to position 1.
3. Set TEST SW to SELF-TEST position.
23UOFX-048
03UOFX.059
I
4. Connect the SST to the System Selector and a ground
5. Set the select switch to position A.
6. Turn the ignition switch to ON.
7. Verify that 88 flashes on the digital display and the buzzer
sounds for 3 sec. after turning the ignition switch ON.
8. If 88 does not flash, check the main relay (FUEL INJ relay)
(Refer to page F-172) power supply circuit, and diagno-
sis connector wiring.
9. If 88 flashes and the buzzer sounds continuously for more
than 20 sec., check for a short circuit between the engine
control unit terminal 1 F and the diagnosis connector. Re-
place the engine control unit if necessary and perform Steps
3 and 7 again.
23UOFX-049 IO. Note any code numbers and check for the causes by refer-
ring to the check sequences shown on pages F-88
through F-103. Repair as necessary.
Note
l Cancel the code numbers by performing the after-
repair procedure following repairs.
(Refer to page F-104.)
I 23UOFX-050
F--83

F SELF-DIAGNOSIS FUNCTION
Troubleshooting
If a service code number is shown on the SST, check for the cause by using the chart related to the code
number shown.
Service code number
CODE LOCATION OF
NO.
MALFUNCTION OUTPUT SIGNAL PATTERN
SELF-DIAGNOSIS FAIL-SAFE
02
Ne-signal
:E nl-u No Ne-signal
-
03 G-signal
(DOHC) No G-signal Cancels 2-group
injection
06* Vehicle speed
sensor ON
OFF No input signal from Shifting performed
vehicle speed normally
sensor
08 Airflow meter ON
OFF Open or short circuit Basic fuel injection
amount fixed as for two
driving modes
(1) Idle switch ON
(2) Idle switch OFF
09 Water
thermosensor ON
OFF Maintains constant 20%
(68OF) command
10 Intake air
thermosensor Maintains constant 20°C
(68OF) command
12
Throttle sensor
“,E l--uL-l Throttle opening judged
as full stroke lockup not
provided
Atmospheric ON Maintains constant
14 pressure sensor command of sea level
(in ECU)
OFF pressure
15 Oxygen sensor
(inactivation) ON
OFF Sensor output
continues less than
0.55V 95 sec. after
engine starts
(1500 rpm) Cancels engine feedback
operation
Oxygen sensor ON Sensor output Cancels engine feedback
17
(Inversion) continues uncharged operatron
OFF 50 sec. after engine
exceeds 1500 rpm
Solenoid valve ON
25 (pressure
regulator)
OFF u 1 nnluln Open or short crrcurt
“If the marked code numbers appeor, refer to Section K
F-84