1992 MAZDA PROTEGE coolant temperature

F OUTLINE
I Component
I Function
I Remark
I
Three-way
solenoid
valve vIcs*
Pressure
regulator
control
Controls vacuum to shutter valve actuator
Controls vacuum to pressure regulator Cuts vacuum when engine speed above
5.000 ram
Cuts vacuum just after starting when engine
hot starting Vacuum chamber
(DOHC)
Water thermosensor
Stores vacuum for use during wide open For WCS*
throttle
Detects coolant temperature; sends signal to
ECU
l WCS: Variable Inertia Charging System 23UOFX-013
F-l 8

F TROUBLESHOOTING GUIDE
Troubleshooting chart
6 I
CRANKS NORMALLY BUT HARD TO START - WHEN ENGINE COLD
*Engine cranks at normal speed but requires excessive crankmg time before starting
IESCRIP-
l Batterv in normal condition
llON l Restans OK after warmup l Engine runs normally at idle [If Idle condrtron is not OK, refer to “Rough idle” (Nos. S-12)]
TROUBLESHOOTING HINTS]
B Air/Fuel mrxture too rrch @Air/Fuel mixture too lean
l Arrflow meter stickrng l Fuel iniectron control malfunction
l Aw cleaner element clogged
*Idle weed control malfunction (Correction for coolant temperature)
0 Poor atomizatron
- ~~ ~~ *Low RVP (summer) fuel is used rn cold weather >
f INSPECTION T Check If “00” is displayed on Self-Diagnosis
Checker wth Ignition switch ON -
Yes
No CT page F-73
SYSTEM SELECT: 1
“SELECT SW: A
Check if ECU terminal voltages are OK
(Especially 1C. 2D. and 2Q)
cc page F-144
Check If engine starts easily when throttle valve -
Yes
-
NO
-
Yes ACTION
Go to next step
Malfunctlon Code No. dlsplayed
Check for cause (Refer to specified
check sequence)
“58” flashes CT- page F-79
Check ECU terminal 1F voltage
Speciflcetlon: Battery voltage CT page F-144
(Ignition ewltch ON)
+ If OK, replace ECU CT page F-143
e If. not OK, check wrring between
ECU and Self-Diagnoos Checker
Go to next step
Check for cause CI page F-145
(-!hnrlr ,‘ ICP ..-I..- .^ nv
c+ page F-103
13UOFX-009
DESCRIPTION:
Further describes the symptom. Confirm that the chart addresses the actual symptom before beginning
troubleshooting.
TROUBLESHOOTING HINTS:
This describes the possible point of malfunction.
STEP:
This shows the order of troubleshooting. Proceed with troubleshooting as indicated.
INSPECTION:
This describes an inspection to quickly determine the malfunction of parts. If a detailed procedure is necessary
to perform the INSPECTION, refer to the page shown by the “~7” mark.
ACTION:
This recommends the appropriate action to take as a result (Yes/No) of the INSPECTION. How to perform
the action is described on the reference page shown by the “~7” mark.
OWOFX-016
F-26

F TROUBLESHOOTING GUIDE
3 CRANKS NORMALLY BUT WILL NOT START (PARTIAL COMBUSTION) - WHEN ENGINE COLD
DESCRIP- *Engine cranks at normal speed but shows only partial combustion and will not continue to run
TION
l Battery in normal condition
*Fuel in tank
[TROUBLESHOOTING HINTS]
0 Air/Fuel mixture too rich
*Air cleaner element clogged
l Airflow meter stuck @ Low engine compression
@ Air/Fuel mixture too lean
l Fuel injection control malfunction
(Correction for coolant temperature)
*Low fuel line pressure
*Air leakage of intake air system
Checker with ignition switch ON
CT page F-83
w page F-150
Specification: Battery voltage
(Ignition switch ON)
W: SELF TEST w page F-149
Fuel line pressure:
285-314 kPa (2.7-3.2 kg/cm’, 38-48 psi) If fuel line pressure quickly in-
creases, check pressure regulator CF- page F-129
d If fuel line pressure gradually in-
creases check for clogging be-
I pump and pressure
Check if fuel return hose is clogged or
F-32

F TROUBLESHOOTING GUIDE
4
CRANKS NORMALLY BUT WILL NOT START (PARTIAL COMBUSTION) - AFTER WARM-UP *Engine cranks at normal speed and shows partial combustion but will not continue to run after running and
DESCRIP- hot soaked
TION *Battery in normal condition
*Engine starts normally when cold
[TROUBLESHOOTING HINTS] 3 Air/Fuel mixture too rich
@ Vapor lock
l Insufficient fuel injection control
*Fuel pressure not held in fuel line after engine stopped
(Correction for coolant temperature)
*High RVP (winter) fuel used in warm weather
l Injector fuel leakage @ Pressure regulator control system malfunction [BP]
switch ON, then check if en
D‘ page F-134
Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm’, 36-46 psi) ne pressure w
+ If fuel line pressure quickly in-
if fuel return hose is clogged
or
F-=34

F TROUBLESHOOTING GUIDE
5
CRANKS NORMALLY BUT HARD TO START - ALWAYS
DESCRIP- l Engine cranks at normal speed but requires excessive cranking time before starting
TION l Battery in normal condition
*Engine runs normally at idle [If idle condition not OK, refer to “Rough idle” (Nos. 8-12)J [TROUBLESHOOTING HINTS]
@ Air/Fuel mixture too lean
@ Air/Fuel mixture too rich l Fuel injection control malfunction
(Correction for coolant temperature) *Air cleaner element clogged
l Airflow meter stuck
*Low fuel line pressure
l Air leakage @ Poor ignition spark
;TEP INSPECTION ACTION
1
Check if “00” is displayed on Self-Diagnosis Yes Go to next step
Checker with ignition switch ON W page F-82 No
Service Code No. displayed
Check for cause (Refer to specified SYSTEM SELECT: 1 check sequence) w page F-83
“88” flashes
Check ECU terminal 1F voltage w page F-150
Specification: Battery voltage
(Ignitlon switch ON)
* If OK, replace ECU w page F-149
W: SELF TEST c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker
2 Check for correct intake manifold vacuum at idle
Yes Go to next step
VsCUUm: More than 450 mmHg (17.7 inHg) No Check for air leakage of intake air sys-
tem components
3 Check if air cleaner element is clean
Yes Go to next step w page F-79
No
Replace air cleaner element
4 Check if engine starts easily when throttle valve Yes Check throttle valve for carbon deposit
quarter open and then go to Step 6 Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm*, 38-46 psi)
(Vacuum hose to pressure regulator dis-
pressure while pinching
c3 If fuel line pressure quickly in-
creases, check pressure regulator w page F-129
c3 If fuel line pressure gradually in-
creases, check for clogging be-
tween fuel pump and pressure
If not clogged, check fuel pump
maximum pressure W- page F-126
F-36

F TROUBLESHOOTING GUIDE
6 CRANKS NORMALLY BUT HARD TO START - WHEN ENGINE COLD
l Engine cranks at normal speed but requires excessive cranking time before starting )ESCRIP-
l Battery in normal condition UON
*Restarts OK after warm-up
*Engine runs normally at idle [If idle condition is not OK, refer to “Rough idle” (NOS. 8-124 [TROUBLESHOOTING HINTS]
3 Air/Fuel mixture too rich
@ Air/Fuel mixture too lean l Airflow meter sticking l Fuel injection control malfunction
*Air cleaner element clogged
(Correction for coolant temperature)
l Idle speed control malfunction
@ Poor atomization
*Low RVP (summer) fuel is used in cold weather
SYSTEM SELECT: 1
Check ECU terminal 1 F voltage CT- page F-150
Specification: Battery voltage
(Ignition switch ON)
c3 If OK, replace ECU CT page F-149 c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker Vacuum: More than 450 mmHg (17.7 inHg)
.
No
Check for air leakage of intake air sys-
tem components
5 Check if air cleaner element is clean Yes
Go to next step
~7 page F-79
No
Replace air cleaner element
6 Disconnect ISC valve connector at idle and
Yes Go to next step
check if engine speed increases CT page F-l 16
No
Replace ISC valve CT page F-109
--’
F-38

F TROUBLESHOOTING GUIDE
9
ROUGH IDLE/ENGINE STALLS AT IDLE - BEFORE WARM-UP
DESCRIP-
*Engine speed low or engine stalls or vibrates excessively at idle during warm-up
TION
[TROUBLESHOOTING HINTS]
@ Low intake air amount
@ Low fuel injection control
l Airflow meter stuck
*Fuel injection control malfunction
*Air cleaner element clogged
(Correction for coolant temperature)
*Air valve
@ Poor atomization
*Low RVP (summer) fuel used in cold weather
w page F-83
W: SELF TEST Check ECU terminal 1F voltage
w page F-150
Specification: Battery voltage
(Ignition switch ON)
c3 If OK, replace ECU c3 page F-149
* If not OK, check wiring between
ECU and Self-Diagnosis Checker
Vacuum: More than 450 mmHg (17.7 inHg)
AX.. Especially 2B, 2E and 30
w page F-150
NO Check for cause CT page F-181
5 Disconnect ISC valve connector and check if en-
Yes Go to next step
gine speed increases after warm-up
CT page F-l 18
No Replace ISC valve c3 page F-109
F-44

TROUBLESHOOTING GUIDE F
s TEP INSPECTION ACTION
6 Check for correct water thermosensor resistance
Yes Go to next step
w page F-158
RESISTANCE
WI
20
‘70
I No Replace water thermosensor w page F-158
A.7
0.5
lE 41
(1400,
(1%) COOLANT TEMPERATURE OC (OF)
Connect System Selector to diagnosis connector
Check if engine speed decreases as engine
Ignition timing (BTDC)
l BP DOHC : go-11 * l BP SOHC : 4*-6O
23UOFX-OS
F-45