engine MAZDA PROTEGE 1992 Workshop Manual

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

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 ENGINE TUNE-UP
ENGINE TUNE-UP
PREPARATlON
SST
I
I I
49 BO19 9AO
System Selector For
inspection of igni-
tion timing and
idle speed
hA ‘I
03UOFX-04
03UOFX-04
03UOFX-04
NG POINT
03UOFX-04 03UOFX-045
BASIC INSPECTION
Engine Oil
1. Remove the engine oil level gauge and check the engine
oil level and oil condition.
2. Add or change the oil as necessary.
Coolant
Warning
l Never remove the radiator cap while the engine is
hot.
l Wrap a thick cloth around the cap before carefully
removing it.
1. Remove the coolant level gauge from the coolant reservoir.
2. Check that the coolant level is between the L and F marks
of the gauge.
3. Add coolant if necessary.
Battery
1. Check for corrosion on the terminals and for loose cable
connections. If necessary, clean the clamps and tighten
them firmly.
2. Check that the electrolyte level is between the UPPER LEV-
EL and LOWER LEVEL marks.
3. Add distilled water if necessary.
4. Check the specific gravity with a hydrometer.
Gravity: 1.27-l .29 (at 20% [68OF] )

ENGINE TUNE-UP F
03UOFX.051
03UOFX-051
- w4TEN I
Air Cleaner Element
Inspection
1. Check the air cleaner element for excessive dirt, damage,
or oil.
Caution
l Do not use compression air to clean the element.
2. Replace the element if necessary.
ADJUSTMENT
Preparation
1. Warm up the engine to normal operating temperature.
2. Turn all electric loads OFF.
3. Connect the
SST to the diagnosis connector.
4. Connect a timing light.
5. Connect a tachometer to the diagnosis connector
IG- ter-
minal as shown.
6. Set switch @to position 1.
7. Set TEST SW to SELF-TEST.
Note
l If the SST is not used, jump across the TEN termi-
nal and the GND terminal of the diagnosis con-
nector.
Ignition Timing
1. Perform “Preparation”. (Refer to above.)
2. Check if the timing mark (yellow) on the crankshaft pulley
and the mark on the timing belt cover are aligned.
Specification:
Engine
Ignition Timing BTDC B6 BP SOHC BP DOHC
6O-8* 4O--6O go-110
SOHC DOHC
I 03UOFX-054
3. If the marks are not aligned, loosen the distributor lock bolts,
and turn the distributor to make the adjustment.
4. Tighten the distributor lock bolts to the specified torque.
Tightening torque:
19-25 N#m (1.9-2.6 m-kg, 14-19 ft-lb)
5. Disconnect the SST.
F-79

F ENGINE TUNE-UP
23UOFX-046 Note
l When the parking brake is not applied, the idle
speed for ATX model (Canada) is approx. 800 rpm. Idle Speed
1. Perform “Preparation”. (Refer to page F-79.)
2. Apply parking brake.
3. Check that the idle speed is within specification.
Idle speed (Neutral or P range): 700-800 rpm
Caution
l Check the idle speed without the electric cooling
fan operating.
4. If not within the specification, adjust the idle by turning the
air adjusting screw.
5. Disconnect the SST.
F-80

ENGINE TUNE-UP F
MEMO
F-81

F SELF-DIAGNOSIS FUNCTION
SELF-DIAGNOSIS FUNCTION
DESCRIPTION
The engine control unit (integrated with the EC-AT control unit) has built-in Self-Diagnosis function the same
as for the previous models. When trouble occurs in the main input devices or output devices, they are indi-
cated and retrieved from the engine control unit (ECU) as service code numbers.
When inspecting for service code(s) memorized in the ECU use the Self-Diagnosis checker and system selector
(SST).
Note
l The ECU constantly checks for malfunction of the in put devices. But, the ECU checks for
malfunction of output devices only in a three second period after the ignition switch is turned
ON and the TEN terminal of the diagnosis connector is grounded.
-
-
INPUT =
SIGNALS-
-
-
- SELF-
DIAGNOSTIC
L!
I-
FUNCTION ENGINE CONTROL
UNIT
j FAIL-SAFE
FUNCTION
I
SYSTEM SELF-DIAGNOSIS
SELECTOR
CHECKER
MIL
(MALFUNCTION
INDICATOR LAMP)

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