1992 MAZDA PROTEGE check engine

FUEL PUMP CONNECTOR
/
REAR SEAT C
FUEL SYSTEM F
PRECAUTION
Fuel Pressure Release and Servicing Fuel System
Fuel in the fuel system remains under high pressure even 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 fire.
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 stalls, turn off the ignition switch.
5. Reconnect 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 fuel leakage.
9MUOF2-122 OBUOFX-126
DlAGNOS&O,NNECTOR
03UOFX-12.
-
DISCONNECT CONNECTOR
/ TO RELEASE FUEL PRESSURE
03UOFX-12;
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 sec. and check
for fuel leaks.
3. Turn the ignition switch OFF and remove the jumper wire.
SYSTEM OPERATION
Fuel Pressure Hold Inspection
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 above.)
F-121

FUEL SYSTEM F
STA
OBUOFX- 15
03UOFX-15
DISCONNECT CONNECTOR
TO RELEASE FUfL PRESSURE
REAR SEAT C
23UOFX-11
INSTALL CLAMPS
CIRCUIT OPENING RELAY
Inspection
Voltage inspection
I, Check voltage between the following terminals and a ground
using a voltmeter.
Ve: Battery voltage
Resistance inspection
1, Check resistance between the terminals using an ohmmeter.
Terminal Resistance (Q)
STA-El 21-43
B-Fc 109-226
B-Fp 00
Replacement
1, Remove the passenger side wall.
2. Disconnect the relay connector.
3. Remove the relay from ECU bracket.
4. Install in the reverse order of removal.
PRESSURE REGULATOR
Inspection
Fuel line pressure
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.)
1, Disconnect the negative battery terminal.
2. Connect a fuel pressure gauge between the fuel filter and
the fuel main hose. (Install clamps as shown.)
3. Connect the negative battery terminal.
4. Start the engine and run it at idle.
5. Measure the fuel line pressure.
Fuel line pressure:
206-255 kPa (2.1-2.6 kg/cm2, 30-37 psi)
6. Disconnect the vacuum hose from the pressure regulator
and measure the fuel line pressure.
Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm2, 36-46 psi)
F-l 29
03UOFX-157

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

PRESSUREREGULATORCONTROLSYSTEM F
03UOFX-17
*
03UOFX-14!
OSUOFX-17
SOLENOID VALVE (PRESSURE REGULATOR CONTROL)
Inspection
On-vehicle
1. Start the engine and run it at idle.
2. Disconnect the vacuum hose (Orange) from the pressure
regulator. Verify that vacuum is felt.
3. Ground the solenoid valve terminal-wire G/O with a jumper
wire. Verify that no vacuum is felt.
4. If vacuum exists, check the solenoid valve.
Solenoid Valve
1. Disconnect the vacuum hose from the solenoid valve and
vacuum pipe.
2. Blow through the solenoid valve from port @
3. Verify that air flows from port @.
4. Disconnect the solenoid valve connector.
5. Connect battery voltage and a ground to the terminals of
the solenoid valve.
6. Blow through the solenoid valve from the port @.
7. Verify that air flows from the valve air filter.
8. If not as specified, replace the solenoid valve.
F-l 35

EVAPORATIVE EMISSION CONTROL SYSTEM t
EVAPORATIVE EMISSION CONTROL SYSTEM
DESCRIPTION
/ /
ENGINE ENGINE
CONTROL CONTROL - INPUT - INPUT
UNIT UNIT
- -
SOLENOID VALVE SOLENOID VALVE k k / /
CHECK VALVE CHECK VALVE
(TWO-WAY) (TWO-WAY)
CHARCOAL CHARCOAL
CANISTER CANISTER
CHECK-AND-CUTC CHECK-AND-CUTC
VALVE VALVE
SEPARATOR SEPARATOR TO ENGINE TO ENGINE SIGNALS
The evaporative emission control system consists of the separator, the check-and-cut valve, the two-way
check valve, the charcoal canister, the purge control solenoid valve, the engine control unit (ECU), and the
input devices. The amount of evaporative fumes introduced into the engine and burned is controlled by the
solenoid valve to correspond to the engine’s operating conditions. To maintain best engine performance,
the solenoid valve is controlled by the ECU.
Operation
.._ The solenoid valve (purge control) is controlled by duty signals from the ECU to perform purging of the char-
coal canister. Purging is done when these conditions are met:
(1) After warm-up
(2) Driving in gear
(3) Accelerator pedal depressed (idle switch OFF)
(4) Oxygen sensor functioning normally
F-l 39

F EVAPORATIVE EMISSION CONTROL SYSTEM
03UOFX-17! 3
03UOFX-180
INSTALLATION DIRECTION
F-l 40
I
23UOFX-126
03UOFX-18
OSUOFX-l&
SYSTEM OPERATION
1 Warm up the engine to normal operating temperature and
run it at idle.
2. Disconnect the vacuum hose from the solenoid valve as
shown in the figure, and verify that no vacuum is felt at the
solenoid valve. -.
3. If not as specified, check the solenoid valve.
SOLENOID VALVE (PURGE CONTROL)
Inspection
1. Disconnect the vacuum hoses from the solenoid valve.
2. Verify that no air flows through the valve.
3. Disconnect the solenoid valve connector and supply bat-
tery voltage as shown in the figure.
4. Verify that air flows through the valve.
5. If not as specified, replace the solenoid valve.
SEPARATOR
Inspection
1. Remove the left side trim.
2. Remove the separator.
3. Visually check the separator for damage. Replace it if
necessary.
CHECK VALVE (TWO-WAY)
Inspection
1. Remove the valve.
2. Check the operation of the valve with a vacuum pump.
Apply approx. 37 mmHg (1.46 inHg)
vacuum at port A Airflow
Apply approx. 44 mmHg (1.73 inHg)
vacuum at port B Airflow

F DECELERATION CONTROL SYSTEM
DECELERATION CONTROL SYSTEM
DESCRIPTION
The dashpot is used to prevent the throttle valve from suddenly closing
03UOFX-185
1
DASHPOT
Inspection
1. Open the throttle valve fully. Push the dashpot rod with a
finger and verify that it goes into the dashpot slowly.
2. Release the rod and check that it comes out quickly.
3. Replace the dashpot if not as specified.
,,
OBUOFX-18
4. Warm up the engine and run it at idle.
5. Connect a tachometer to the diagnosis connector IG-
terminal and increase engine speed to 4,000 rpm.
6. Slowly decrease the engine speed and check that the le-
ver touches the dashpot rod at the specified speed.
Specification:
l B6 ..**.............,....,.............. Approx. 3,000 rpm
l BP SOHC . ..*..................*.... Approx. 2,700 rpm
l BP DOHC . . . . . . . . . . . . . . . . . . . . ...“... Approx. 3,500 rpm
7. If not as specified, loosen the locknut and turn the dashpot
to adjust.
F-l 42

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