engine MAZDA PROTEGE 1992 Workshop Manual

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

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

CONTROL SYSTEM F
CONTROLSYSTEM
PREPARATION
SST
49 9200 162
Engine Signal
Monitor
49 HO18 9Al
Self-Diagnosis
Checker
49 GO1 8 904
Sheet For
inspection of
ECU
For
inspection of
oxygen sensor
For
inspection of
ECU 49 GO18 903
Adapter
harness
49 BO19 9AO
System
Selector For
inspection of
ECU
For
inspection of
oxygen sensor
03UOFX-20
F-l 47

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 F
SMALL TYPE
03UOFX.20:
03UOFX-20
23UOFX-13
TERMINALS
AANDB
c “.w a ,.1/M rrmrrm
_-
03UOFX-201
ENGINE CONTROL UNIT (ECU)
Removal / Installation
1. Remove the side walls (driver’s side and passenger’s side).
(Refer to page S-94.)
2. Remove the bolts and nuts.
3. Disconnect the ECU connectors.
4. Install a
new ECU in the reverse order of removal.
Inspection
1. Disconnect the ECU connectors.
2. Connect the
SSTs (Engine Signal Monitor and Adapt-
er)
to the ECU as shown,
3. Set the SST (Sheet) on the Engine Signal Monitor with
the specified side fancing up as shown.
Note
l MTX...48 PIN
l ATX...84 PIN
4. Measure the voltage at each terminal.
(Refer to pages F-150 to F-167.)
5. If any ECU terminal voltage is incorrect, check the related
input or output devices and wiring. If no problem is found,
replace the ECU. (Refer to above.)
Caution
l Never apply voltage to SST terminals A and B.
F-l 49

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

F CONTROL SYSTEM
Ve: Battery voltage
erminal Input Output Connection to
Test condition Correct voltage Remark
2s 0 Solenoid valve
Engine speed below 5,000 rpm ov VICS: Variable In-
(VICS)
Engine speed above 5,000 rpm
VB ertia Charging
System [DOHC]
2T 0 Solenoid valve
60 [DOHC]/120 [SOHC] seconds after ov
(Pressure regula- engine started when engine coolant tem-
tor) [BP] perature above 90% (194OF) and intake
-
air temperature above 58% (136’F)
[DOHC]/50% (122OF) [SOHC]
Other condition at idle
Ve
2u
0 Injector (Nos. 1, 3) Ignition switch ON V0 *Engine Signal
idle
VB Monitor: Green
Engine speed above 2,000 rpm on de-
VB and red lamps
flash
celeration (After warm-up)
2v 0 Injector (Nos. 2, 4) Ignition switch at idle
Ve
idle
VI3
Engine speed above 2,000 rpm on de-
VB celeration (After warm-up)
2w
0 ISC valve Ignition switch ON Approx. 7V
-
Idle
Approx. QV
2x 0 Solenoid valve Ignition switch ON
VB (Purge control) -
Idle VB
2Y - - - - - -
23UOFX-1:
I r
U----l l-l
Ll I-
2y
2w 2u 2s 20 20 2M 2K 21 23 2E 2C 2.4 1U 1s 10 10 1M 1K 11 1G 1E 1~ IA
2z 2x 2’4 2T 2R 2P 2N 2L 2J 2l-i 2F 2D 28 IV 1T 1R lp IN IL 1J 1~ 1F If) 1~ -/
F-l 56