1992 MAZDA PROTEGE coolant

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] )

SELF-DIAGNOSIS FUNCTION
:ODE No. 09 (WATER THERMOSENSOR)
iTEP INSPECTION ACTION
1 Check water thermosensor circuit for poor con-
Yes Repair or replace connector
nection
3 Check if resistance of water thermosensor is OK Yes Go to next step
Coolant temp. Resistance (kg)
No Replace water thermosensor
-20% ( -4OF) 14.6-17.8
2o”c ( 68OF) 2.21-2.69
80% (176OF) 0.29-0.35
4 Check if same Code No. is present following Yes Go to next step
after-repair procedure
w page F-104 No
Water thermosensor and circuit OK
5 Check if ECU terminals voltages are OK
Yes Replace ECU w page F-149
MTX...2D and 20
ATX...2E and 3D
w page F-152 No Check for short circuit in wiring from
water thermosensor to ECU
-- ._-..__
23Uu~X-ut
4
-’
F-92

INTAKE AIR SYSTEM F
I 23UOFX-096
INTAKE MANIFOLD
Installation Note
BP
1, Tighten the bolts in the order shown in the figure.
Tightening torque:
19-25 N-m (1.9-2.6 m-kg, 14-19 ft-lb)
B6
1. Tighten the bolts in the order shown in the figure.
Tightening torque:
19-25 N-m (1.9-2.6 m-kg, 14-19 ft-lb)
2. Refill the radiator with the specified engine coolant.
(Refer to page F-78.)
3. Check for engine coolant leakage.
F-113

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.

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

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
VB: Battery voltage
erminal Input Output Connection to Test condition Corrsct voltage Remark
1M - - - - - -
IN 0 Throttle sensor Accelerator pedal released ov Ignition switch
(Idle switch)
Accelerator pedal depressed
VB ON
10 0
1P 0 Stoplight switch
P/S pressure
switch Brake pedal released
Brake pedal depressed
Ignition switch ON
P/S ON at idle
P/S OFF at idle ov
-
VEi
Va
ov
VS -
10 0 A/C switch A/C switch ON
A/C switch OFF Below 23 Ignition switch
VS ON and blower
motor ON
1R 0
IS 0 Fan switch
Blower control
switch Fan operating (Engine coolant tempera-
ture over 97% (207OF) or diagnosis con-
nector terminal TFA grounded)
Fan not operating (Idle)
Blower control switch OFF or 1st position
Blower control switch 2nd or higher po-
sition ov
-
V0
Ve ignition switch
ov ON
IT 0 Rear window
defroster switch Rear window defroster switch OFF
Rear window defroster switch ON ov
VB
Ignition switch ON
1u 0
iv 0 Headlight switch
Neutral/Clutch
switches Headlights ON
Headlights OFF
Neutral position or clutch pedal
depressed
Others V0
-
ov
ov
VB -
1 I lr----t
r-i
ul r
2Y 2w 2u 2s 20 20 2M 2K 21 2G 2E 2’3 2A 1lJ 1s IQ 10 1M 1K 11 1G 1E 1~ 1A
22 2x 2v 2T 2R 2P 2N 2L 2J 34 2t= 2D 28 Ii/ fT 1R 1p IN 1L 1J 1H 1F 1D 18
F-l 52

CONTROL SYSTEM
Ve: Battery
arminal Input Output Connection to lest condition Correct voltage Remark
2A - - Ground (Injector) Constant ov -
28 - - Ground (Output) Constant ov -
2c - - Ground (CPU) Constant ov -
2D - - Ground (Input) Constant ov -
2E 0 Distributor Ignition switch ON
Approx. OV
(Ne-signal) or 4.5-5.5V -
Idle Approx. 2V
2F - - - - - -
2G 0 Distributor Ignition switch ON Approx. OV
(G-signal) [DOHC] or 4.5-5.5V
Idle Approx. 1.5V
2H 0 Ground (California) Constant ov
-
Main relay Ignition switch ON Va
(Canada)
21 - - - - - -
2J 0 Open Constant Approx. l-29 -
2K 0 Throttle sensor Constant 4.5-5.5v
(ATX)/Airflow meter
-
2L 0 Throttle sensor
(Power switch) Accelerator pedal released
Accelerator pedal fully depressed Approx. 4.5~5%
ov -
2M 0 Throttle sensor Accelerator pedal released
Accelerator pedal fully depressed Approx. 0.5V
Approx. 4.OV -
2N 0 Oxygen sensor Ignition switch ON ov
Idle (Cold engine) ov
Idle (After warm-up) O-l .ov -
Increasing engine speed (After warm-up) 0.5-I .ov
Deceleration o-0.4v
20 0 Airflow meter Ignition switch ON Approx. 3.8V
-
Idle Approx. 3.3V
2P 0 Intake air ther- Ambient air temperature 20% (68OF) Approx. 2.5V Built in airflow
mosensor meter
2Q 0 Water thermo- Engine coolant temperature 20% (68’F) Approx. 29
_
sensor
After warm-up Below 0.5V
2R - - - - -
- 711 ICIFX-12 voltage
_““_. ,. .I 7
1 r u-
r-i Ll r
2Y 2w 2u 2s 20 20 2M 2K 21 2G 2E 2~2 2A 1U 1s 1Q 10 lft,j ,K ,, ,G ,E ,c ,A
22 2x 2v 2T 2R 2P 2N 2L 2J 2H 2F 2D 28
IV 1T fR 1p 1N 1L 1J ,H IF ID ,B
F-l 54