1992 MAZDA PROTEGE engine

F IDLE SPEED CONTROL (ISC) SYSTEM
PREPARATION
SST
OBUOFX-113
OSUOFX-I 14
I
23UOFX-095
J 03UOFX-1 lf
23UOFX-101
F-116
SYSTEM OPERATION
Air Valve
Note
l This inspection must be done with the engine cold.
- Engine coolant below 20°C (68°F).
1. Connect the SST to the diagnosis connector.
2. Set the switch @to position 1 and TEST SW to SELF-TEST.
3. Start the engine.
4. Check if the idle speed decreases gradually as the engine
warms up.
ISC Valve
1. Warm up the engine.
2. Check if a click sound is heard and the engine speed in-
creases to approx. 1,200 rpm when the ISC valve con-
nector is disconnected at idle.
3 If the engine speed does not change, replace the ISC valve.
4. Reconnect the connector.
ISC VALVE
Inspection
1. Disconnect the ISC valve connector.
2. Check the resistance of the ISC valve.
Resistance: 11-130 (at 20°C [68*F])
3. If not as specified, replace the ISC valve.
AIR VALVE
Inspection
1. Remove the air valve. (Refer to page F-109.)
2. Cool the air valve at below O°C (32OF).
3. Heat the air valve at @by using a drier and verify that part
@moves in the direction of the arrow in the figure.

VARIABLE INERTIA CHARGING SYSTEM (VICS)
SYSTEM OPERATION
DIAGNOSIS 1. Connect the tachometer to the IG- terminal of the diagno- CONNECTOR sis connector.
2. Start the engine and run it at idle.
3. Verify that the rod of the shutter valve actuator has pulled -
inward.
OSUOFX-I 19
F-118
i-..
1”
03UOFX-I 2
23UOFX-1 C
23UOFX-1 C
23UOFX-IC
4. increase the engine speed gradually and verify that the rod
is extended when the engine speed reaches 5,000 rpm.
SHUTTER VALVE ACTUATOR
Inspection
1. Remove the vacuum hose from the actuator.
2. Verify that the rod can move in and out smoothly.
3. Start the engine and run it at idle.
4. Place a finger over the end of vacuum hose and verify that
there is vacuum.
5. Install the vacuum hose and verify that the rod is pulled
inward.
SOLENOID VALVE (VICS)
Inspection
1. Remove the three-way solenoid valve.
2. Verify that air flows between each port as below.
Port
@--@ - -
@-0
@ --- (g Air flow
No
No
Yes
3. Connect battery voltage and a ground to the terminals of
the solenoid valve.
4. Verify that air flows between each port as below.
Port Air flow
-_I
-I_
@- 03 Yes
@l-o No
@--0 No

F FUEL SYSTEM
FUEL SYSTEM
DESCRIPTION
FUEL FILTER
(HIGH PRESSURE SIDE) . TANK
FUEL PUMP
PRESSURE SIDE)
OWOFX-12
This system supplies the necessary fuel for combustion at a constant pressure to the fuel injectors. Fuel is
metered and injected into the engine intake ports according to injection control signals from the engine con-
trol unit. The system consists of the fuel tank, the fuel pump, the fuel filters, the delivery pipe, the pressure
regulator, the fuel injectors, and the circuit opening relay. ._*
F-l 20

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

FUEL SYSTEM I-
9MUOF2-17
INJEC
GRO
,:.: ‘.L.. :
,;:y :.*‘.
+:: ..y&
..: .:: ,: ,:y>
‘$pID~~ :i
..,..:,:,
,.,i. :)I,
./[::/: :
. ...:;.
/jj,.‘, ;.::,::
.’ .::: ij!/ji..
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