fuel MAZDA PROTEGE 1992 Owners Manual

231JOFX-1
FUEL SYSTEM F
INJECTOR
Inspection
Operation check
1. Warm up the engine and run it at idle.
2. Listen for operational sound of each injector with a screw-
driver or a sound scope.
3. If no sound is heard, measure injector resistance.
4. If the injector resistance is OK, check wiring to the injector
and the voltages of the ECU terminals MTX (2A, 2U and
2V) ATX (3A, 3U and 3V).
(Refer to page F-152.)
Injector resistance
1. Disconnect the injector harness.
2. Measure resistance of the injector with an ohmmeter.
Resistance: 12-l 6Q
3. If not as specified, replace the injector.
03UOFX-1
DISCONNECT CONNECTOR
TO RELEASE FU5L PRESSUR
REAR SEAT C
23UOFX-1
OBUOFX-
GRQMMET
INSULATOR
c5
OSUOFX-
Removal
Warning
l Before performing the following operation, release
the fuel pressure from the fuel system to reduce the
possibility of injury or fire. (Refer to page F-121 .)
l When removing the fuel system components, keep
sparks, cigarettes, and open flames away from the
fuel.
1. Disconnect the connectors from the injectors.
2. Remove the injector harness from the delivery pipe.
3. Remove the bolts from the intake manifold.
4. Remove the delivery pipe with the injectors and the pres-
sure regulator.
5. Remove the injectors, grommets, and insulators.
F-131

l Be extremely careful when working with fuel. I
23UOFX.121 Always work away from sparks or open flames.
3. Connect the diagnosis connector terminals F/P and GND
with a jumper wire.
FUEL SYSTEM
Fuel leakage test
1. Remove the injectors with the delivery pipe.
(Refer to page F-l 31.)
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
4. Turn the ignition switch ON.
03UOFX-16’
23UOFX-12 9 5. Tilt the injectors approx. 60 degrees and verify that no fuel
leaks from the injector nozzles.
6. If fuel leaks from an injector, replace it.
Note
l After 1 minute a small amount of fuel leakage from
the injector Is acceptable.
7. Turn the ignition switch OFF and remove the jumper wire.
-i
F-l 32

FUEL SYSTEM I-
9MUOF2-17
INJEC
GRO
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OSUOFX-17
T MANIFOLD DELIVERY’ PIPE
MUOFX-17
Installation
Install in the reverse order of removal, referring to Installa-
tion Note.
Tightening torque:
Delivery pipe
19-25 N.m (1.9-2.6 m-kg, 14-19 ft-lb)
Installation note
1. Use new injector O-rings.
2. Apply a small amount of clean engine oil to the O-rings be-
fore installing.
3. Install new injector insulators.
4. Install the injectors.
F-l 33

F PRESSURE REGULATOR CONTROL SYSTEM
PRESSURE REGULATOR CONTROL SYSTEM (BP ENGINE)
THERMOSEN
SOLENOID VALVE
(PRESSURE REGULATOR CONTROL)
(FROM DELIVERY
FUEL
(TO FUEL TANK)
Engine
BP SOHC
BP DOHC Coolant temperature
Above 90% (194*F) Operating condition
Intake air temperature
Above 50°C (122OF)
Above 58OC (136OF) Engine condition . Operating time (set)
Throttle valve fully closed
Approx. 120
or no load condition
Approx. 60
#.nr IAt-%/ 4 7
To prevent percolation of the fuel during hot restart idle, vacuum to the pressure regulator is momentarily
cut, and the fuel injection pressure is increased to slightly more than 284 kPa (2.9 kg/cm2, 41.2 psi).
F-l 34

EVAPORATIVE EMISSION CONTROL SYSTEM F
-l CHECK-AND-CUT VALVE
Inspection
1. Remove the check-and-cut valve.
2. Connect a pressure gauge to the passage connected to
the fuel tank.
3. Blow through the valve from port A and verify that the valve
opens at 6.36-6.34
kPa (0.065-0.065 kg/cm2,
0.92-l 2.09 psi).
4. Remove the pressure gauge and connect it to the passage
to atmosphere.
5. Blow through the valve from port B and verifyjhat the valve
opens at
0.96-4.91 kPa (0.01-0.05 kg/cmL, 0.14-0.71
psi). 1 9MUOF2-194
Note
l The test must be performed with the valve held
horizontally. Otherwise, the ball in the valve will
move out of position and close the passage.
CHARCOAL CANISTER
Inspection
1. Visually check for damage and replace the charcoal canis-
ter if necessary.
F-141

FUEL CUT CONTROL SYSTEM F
FUEL CUT CONTROL SYSTEM
DESCRIPTION
This system is used to improve the fuel economy, to prevent engine bucking during deceleration, and to
protect the engine from overspeeding.
23UOFX-127
PREPARATION
SST
r
49 9200 162
03UOFX.191
l7=---T II USE CPNNECTOR A
03UOFX-19
SYSTEM OPERATION
1. Connect a tachometer to the diagnosis connector IG-
terminal.
2. Connect the
SSTs (Engine Signal Monitor and Adapt-
er)
to the engine control unit (ECU).
3. Warm-up the engine to normal operating temperature and
run it at idle.
Warning
l Confirm that transmission is in Neutral (MTX) or P
range (ATX).
4.
Set the SST (Sheet) on the Engine Signal Monitor with
the specified side fancing up as shown.
Note
l MTX...48 PIN
l ATX...64 PIN
I 23UOFX-128
F-l 43

F FUEL
23UOFX-12:
0-6V
23UOFX- 131
to the terminal 2U or 2V (MTX), 3U or 3V (ATX)
hat the green and red lamps flash alternately.
nd No,3.....ECU terminal 2U (MTX)
3U (ATX)
. . . ..ECU terminal 2V (MTX)
3V (ATX)
6. Increase the engine speed to 4,000 rpm and then suddenly
release the throttle.
7. Verify that the red indicator lamp illuminates while the en-
gine speed is above approx.
1,900 rpm on deceleration.
t aced maximum rpm over 3 sec.
8. Increase the engine speed and verify that the maximum rpm
does not exceed specification.
.
.
. ..“.*..1”*“.-.“.....*......*...
Approx. 7,300 rpm
. . ..I......m....“.....*........m Approx. 6,300 rpm
F-l 44

DECHOKE CONTROL SYSTEM t-
DECHOKE CONTROL SYSTEM
DESCRIPTION
To facilitate starting the engine when the spark plugs become fouled, such as when the engine is flooded,
fuel injection is cut if the throttle valve is held wide open while cranking and the engine coolant temperature
is O°C (32OF) or below. This allows the spark oluas to drv and purges excess fuel from the cylinders.
f-- ECU _
. IGNITION SWITCH (START)
l ENGINE SPEED BELOW 500 rpm ’
l THROTTLE VALVE FULLY OPEN
l ENGINE COOLANT TEMPERATURE ;
BELOW
0% (32°F) I FUEL CUT
OBUOFX-19
I / / ‘ I
SYSTEM OPERATION
1.
2. Check if the engine coolant temperature is below O°C
(32OF).
If the engine coolant temperature is above O°C (32OF), dis-
connect the water thermosensor connector and connect an
approx. 10 kB resistor to the connector.
03UOFX.198 3. Turn the ignition switch to START and verify that the injec-
OBUOFX-19! 3
tor operating sound is heard.
4. Depress the accelerator pedal fully and turn the ignition
switch START. Verify that no injector operating sound is
heard.
F-l 45

F CONTROL SYSTEM
STRUCTURAL VIEW
23UOFX-1:
1. Engine control unit (ECU) 8. Solenoid valve (Pressure regulator control)
- .--
Removal / Installation . . . . . . . . . . . . . . . . page F-149
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page F-149
2. Circuit opening relay
Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 29
Inspection ,...,........................... page F-l 29
3. Clutch switch (MTX)
inspection . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 72
4. Airflow meter (With intake air thermosensor)
Inspection .,..........,...,............... page F-l 68
5. ISC valve
Inspection .,*,........,.,.........,....... page F-116
Removal / Installation . . . . . . . . ,.... page F-l 09
G-Throttle sensor
Inspection . . . . . . . . . . . . , . . . . . . page F- 169
Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 09
7. Solenoid valve (VICS) [DOHC]
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page F-l 18 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9. Water thermosensor
Inspection. . . . . . . .
Removal I Installation ....I..........
10. Solenoid valve(Purge control)
Inspection ,............ ,..................
11, Main relay (FUEL INJ relay)
Inspection. ..,............................
12. Neutral switch (MTX)
Inspection ,.,,,,....I.l,,.........I.......
Replacement . . . . . . .
13. Oxygen sensor
Inspection,. . . .
Replacement . , . . . .
14. P/S pressure switch
Inspection . . ..__.._._._........
Replacement . , . . . . . . . . . . . . . page t-135
page F-l 68
page F--l 68
page F-l 40
page F-172
page F-l 73
page F-173
page F-171
page F-172
--
page F-173
page F-173
F-l 48

CONTROL SYSTEM
Terminal voltage (MTX)
VB: Battery voltage
wminal Input Output Connection to Test condition Correct voltage Remark
1A - - Battery Constant VB For backup
1B 0 Main relay OFF OV
(FUEL INJ relay) Ignition switch ._-
ON VB
1c 0 Ignition switch While cranking Approx. 10V
(START) -
Ignition switch ON ov
10 0 Self-Diagnosis Test switch at “SELF-TEST” With Self-
Checker Lamp illuminated for 3 sec. after ignition 4.5--5.5v Diagnosis Check-
(Monitor lamp) switch OFF+ON er and System
Lamp not illuminated after 3 sec. VEI Selector
Test switch at “02 MONITOR” at idle
Monitor lamp illuminated 4.5-5.5v
Test switch at
“02 MONITOR” at idle
Monitor lamp not illuminated Va
1E 0 Malfunction indica- Lamp illuminated for 3 sec. after ignition
Below 2.5V With System
tor lamp (MIL) switch OFF-ON Selector test
Lamp not illuminated after 3 sec.
VB switch at
“SELF-TEST”
Lamp illuminated Below 2.5V
Lamp not illuminated VR
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. VE - Checker and
Buzzer sounded Below 2.5V System Selector
l With System
Buzzer not sounded
VB Selector test
switch at
“SELF-TEST”
1G 0 Igniter Ignition switch ON ov
-
Idle Approx. 0.2V
1H - - - - - -
_-
II - - - - - -
1J
0 AIC relay Ignition switch ON
VB
A/C switch ON at idle Below 2.5V
A/C switch OFF at idle VB
-
1K 0 Diagnosis
connector
(TEN terminal) System Selector test switch at
“02 MONITOR”
System Selector test switch at
“SELF-TEST” VB
ov Ignition switch
ON
1L 0 DRL relay
(Canada) Parking brake pulled with ignition switch
Ve
l DRL.: Daytime
ON (DRL OFF) Running Lights
Idle (DRL ON) Below 2.5V
V’
F-l 50