Page 316 of 1164
![MAZDA PROTEGE 1992 Workshop Manual F TROUBLESHOOTING GUIDE
13 HIGH IDLE SPEED AFTER WARM-UP
DESCRIP- l Idle speed excessive after warm-up
TION [TROUBLESHOOTING HINTS]
Excessive intake air supplied to engine
@I Throttle valve not f MAZDA PROTEGE 1992 Workshop Manual F TROUBLESHOOTING GUIDE
13 HIGH IDLE SPEED AFTER WARM-UP
DESCRIP- l Idle speed excessive after warm-up
TION [TROUBLESHOOTING HINTS]
Excessive intake air supplied to engine
@I Throttle valve not f](/manual-img/28/57077/w960_57077-315.png)
F TROUBLESHOOTING GUIDE
13 HIGH IDLE SPEED AFTER WARM-UP
DESCRIP- l Idle speed excessive after warm-up
TION [TROUBLESHOOTING HINTS]
Excessive intake air supplied to engine
@I Throttle valve not fully closed
@ Idle speed control malfunction
l Air valve not closed l ISC valve stuck
l ISC valve connector disconnected l A/C, P/S, or E/L signal sent to ECU l Incorrect coolant temperature signal
stalled and operates freely w page F-l 14
@ If OK, go to Step 2
+ If not OK, clean, adjust or replace w page F-l 14
* If contaminated, clean throttle body Dashpot set speed: + If not contaminated, replace throttle
..*.............*..,........,... Approx. 3,000 rpm w page F-109
BP SOHC . . . . . . . . . . . . . . . . . . . . . . Approx. 2,700 rpm
BP DOHC . . . . . . . . . . . . . . . . . . . . . . Approx. 3,500 rpm
w page F-83
Check ECU terminal 1F voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
e If OK, replace ECU w page F-149
c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker
Check for cause (Refer to specified
check sequence) w page F-108
W: SELF TEST
and Self-Diagnosis Checker
F-50
Page 318 of 1164
![MAZDA PROTEGE 1992 Workshop Manual F TROUBLESHOOTING GUIDE
14 IDLE MOVES UP AND DOWN/IDLE HUNTING
DESCRIP-
*Engine speeds up and down periodically at idle
TION
[TROUBLESHOOTING HINTS]
@ idle switch (built in throttle sensor) OFF MAZDA PROTEGE 1992 Workshop Manual F TROUBLESHOOTING GUIDE
14 IDLE MOVES UP AND DOWN/IDLE HUNTING
DESCRIP-
*Engine speeds up and down periodically at idle
TION
[TROUBLESHOOTING HINTS]
@ idle switch (built in throttle sensor) OFF](/manual-img/28/57077/w960_57077-317.png)
F TROUBLESHOOTING GUIDE
14 IDLE MOVES UP AND DOWN/IDLE HUNTING
DESCRIP-
*Engine speeds up and down periodically at idle
TION
[TROUBLESHOOTING HINTS]
@ idle switch (built in throttle sensor) OFF at idle
@ Air leakage
@ Fuel injection amount inconstant
spoor contact point inside airflow meter
@ Poor ignition
iTEP INSPECTION
1 Check if “00” is displayed on Self-Diagnosis
Checker with ignition switch ON
CT page F-82
SYSTEM SELECT: 1
ACTION
Yes Go to next step
No
Service Code No. displayed
Check for cause (Refer to specified
check sequence) w page F-83
“88” flashes
,,;9 Check ECU terminal 1F voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
W: SELF TEST + If OK, replace ECU KIT page F-149
ELECT SW: A + 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
Intake manifold vacuum:
More than 450 mmHg (17.7 inHg)
No Low vacuum
Check for air leakage at intake air
system
3 Check if air cleaner element is clean Yes Go to next step
w page F-79
No Replace air cleaner element
4
Disconnect high-tension lead at idle and check if Yes Go to next step
engine speed decreases equally at each cylinder
No Go to Step 9
5 Check if ECU terminal voltages are OK Yes Go to next step
w page F-150
No Check for cause KII page F-151
6
Connect System Selector to diagnosis connector Yes Go to next step
and set Test Switch to “SELF TEST” and check
for correct ignition timing at idle after warm-up
w page F-79
Ignition timing (BTDC)
l BP DOHC : 9”-11 o l BP SOHC : 4O-8” l B6 : 6O--8O No Adjust ignition timing r-7 page F-79
TEST SWITCH . .
F-52
Page 319 of 1164

TROUBLESHOOTING GUIDE F
No Replace airflow meter
9
Check for injector operating sound at idle Yes Go to Step 11
No Go to next Step
10 Check if battery voltage exists at injector connec- Yes Check if injector resistance is OK CT page F-131
tor (W/R) wire Resistance: 12-l 6fi
c3 If OK, check wiring between ECU
and injector
c3 If not OK, replace injector CT page F-131
No
Check wiring between ECU and injector
11 Check if strong blue spark is visible at discon-
Yes Go to next step
netted high-tension lead
No Check high-tension lead
+ If OK, check distributor cap and
rotor w page G-22
* If not OK, replace high-tension lead
12
Check if spark plugs are OK Yes Check for correct engine compression CT page Bl-10
w page G-16 82-10
Compression (Minimum):
. BP SOHC
834 kPa (8.5 kg/cm2, 121 psi)300 rpm
BON BUILDUP l BP DOHC
883 kPa (9.0 kg/cm*, 128 psi)-300 rpm
l.O-l.lmm ’ B6 DAMAGE AND 932 kPa (9.5 kg/cm’, 135 psi)-300 rpm DETERIORATION
c3 If OK, go to next step
c13 If not OK, check for cause CT page Bl-10
B2-10
No
Clean or replace w page G-18
13
Check for injector leakage Yes Replace injector CT page F-131
w page F-132
No Go
to next step
14 Try known good ECU and check if condition im-
proves cc7 page F-149
23UOFX-030
F-53
Page 320 of 1164

F TROUBLESHOOTING GUIDE
15
ENGINE STALLS ON DECELERATION
DESCRIP-
l Engine unexpectedly stops running while decelerating or after deceleration
TION l Idle condition normal
[TROUBLESHOOTING HINTS]
Engine speed drops too much when releasing accelerator or poor connector connection disconnected by deceleration
force
3 Idle speed control malfunction
3 Fuel cut control malfunction @ Idle speed misadjustment
TEP INSPECTION
ACTION
1
Check if idle condition is normal Yes
Go to next step
No Adjust or perform troubleshooting
Nos. 8-11 “ROUGH IDLE” v page F-42
F-48
--
2
Check if “00” is displayed on Self-Diagnosis Yes Go to next step
Checker with ignition switch ON
W page F-82 No
SYSTEM SELECT: 1 Service Code No. displayed
Check for cause (Refer to specified
check sequence) w page F-83
“88” flashes
Check ECU terminal IF voltage LIT= page F-150
Specification: Battery voltage
(Ignition switch ON)
W: SELF TEST + If OK, replace ECU w page F-149
Q If not OK, check wiring between
ECU and Self-Diagnosis Checker
3 Check switches for correct operation with Self-
Yes Go to next step
Diagnosis Checker Monitor Lamp with ignition
switch ON
w page F-105 No
Lamp not ON or OFF with specified
switch
Check for cause (Refer to specified
check sequence) CT page F-106
-,-y/
,’ Lamp always ON
Check wiring between ECU terminal 1 D
and Self-Diagnosis Checker
W: SELF
TEST
4 Check if ECU terminal voltages are OK
Yes Go to next step
MTX...Especially IV, 2D, 20, 2U, 2V and 2Q
ATX... Especially 28, 2E, 30, 3U, and 3V
w page F-150 No Check for cause w page F-151
5
Check for poor connection of following parts
Yes Repair or replace
. Ignition coil
l Igniter l Distributor
-- l High-tension lead
No l Injector Go to next step l Circuit opening relay l ECU
F-54
Page 322 of 1164
![MAZDA PROTEGE 1992 Workshop Manual TROUBLESHOOTING GUIDE
16 ENGINE STALLS SUDDENLY (INTERMITTENT)
DESCRIP- l Engine intermittently stops running
TION l Before stalling, engine condition OK [TROUBLESHOOTING HINTS]
@ Intermittently n MAZDA PROTEGE 1992 Workshop Manual TROUBLESHOOTING GUIDE
16 ENGINE STALLS SUDDENLY (INTERMITTENT)
DESCRIP- l Engine intermittently stops running
TION l Before stalling, engine condition OK [TROUBLESHOOTING HINTS]
@ Intermittently n](/manual-img/28/57077/w960_57077-321.png)
TROUBLESHOOTING GUIDE
16 ENGINE STALLS SUDDENLY (INTERMITTENT)
DESCRIP- l Engine intermittently stops running
TION l Before stalling, engine condition OK [TROUBLESHOOTING HINTS]
@ Intermittently no spark or no-fuel injection caused by ve-
hicle vibration, acceleration, or deceleration
*Poor connection in wire harness
3 INSPECTION
Check if “00” is displayed on Self-Diagnosis
Checker with ignition switch ON c7 page F-82
g
-%ELECT SW: A
Check for poor connection of following parts l ignition coil
l igniter l Distributor l High-tension lead l lniector
l Ci;cuit opening relay l ECU
Check if ECU terminal voltages are OK
MTX...Especially lB, 2A, 28 and 2C
ATX... Especially lB, 3A, 38 and 3C w page F-150
Note
l When checking voltages, tap, move, and
wiggle harness and connector to recreate
problem
Yes
No Service Code No. displayed
Check for cause (Refer to specified
check sequence) Note
l When checking wiring harness and
connectors, tap, move, and wiggle
suspect sensor and/or harness to
recreate problem
“88” flashes
Check ECU terminal IF voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
c3 If OK, replace ECU CT= page F-149
+ If not OK, check wiring between
ECU and Self-Diagnosis Checker
Yes
Repair or replace
No Go to next step
Yes
No
T ACTION
Go to next step w page F-83
Go to Troubleshooting No.2
‘CRANKS NORMALLY BUT WILL NOT
START (NO COMBUSTION)” CT- page F-30
Check for cause D page F-151
F-56
Page 323 of 1164
![MAZDA PROTEGE 1992 Workshop Manual TROUBLESHOOTING GUIDE
17 HESITATES/STUMBLES ON ACCELERATION
bESCRIP-
*Flat spot occurs just after accelerator depressed or mild jerking occurs during acceleration
‘ION TROUBLESHOOTING HINTS]
0 MAZDA PROTEGE 1992 Workshop Manual TROUBLESHOOTING GUIDE
17 HESITATES/STUMBLES ON ACCELERATION
bESCRIP-
*Flat spot occurs just after accelerator depressed or mild jerking occurs during acceleration
‘ION TROUBLESHOOTING HINTS]
0](/manual-img/28/57077/w960_57077-322.png)
TROUBLESHOOTING GUIDE
17 HESITATES/STUMBLES ON ACCELERATION
bESCRIP-
*Flat spot occurs just after accelerator depressed or mild jerking occurs during acceleration
‘ION TROUBLESHOOTING HINTS]
0 Air/Fuel mixture becomes lean when depressing accelerator l Fuel injection control malfunction
(Correction for accelerating condition)
*Air leakage
l Fuel line pressure decreases l Spark advance control malfunction 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
SYSTEM SELECT: 1 Check for cause (Refer to specified
check sequence) w page F-83
“88” flashes
W: SELF TEST Check ECU terminal IF voltage CT= page F-150
Specification: Battery voltage
(Ignition switch ON) c3 If OK, replace ECU c? page F-149 * If not OK, check wiring between
ECU and Self-Diagnosis Checker Vacuum: More than 450 mmHg (17.7 InHg)
tern components
Replace air cleaner element 4
Check if ECU terminal voltages are OK
Yes Go to next step
MTX...Especiaily 2L
ATX... Especially lT, 2F, and 21 w page F-150
No Check for cause cp page F-151
5
Check if throttle linkage is correctly installed and
Yes Go to next step
operates freely w page F-l 14 ~~
Correct, clean, or replace as required
any binding or damaged linkage and
adjust cable deflection at throttle body w page F-l 14
6
Check continuity between throttle sensor termi- Yes Go to next step
nals IDL and E w page F-189
MTX
A-I-X 1
J E
IDL
Clearance between throttle
lever and stopper Continuity
MTX 0.1 mm (0.004 in) Yes
1 .Omm (0.039 in) No
ATX 0.1 mm (0.004 in)
Yes
0.6mm (0.024 in) No
No Adjust w page F-189
F-57
Page 325 of 1164
TROUBLESHOOTING GUIDE
18 SURGES WHILE CRUISING
DESCRIP- *Unexpected change in engine speed which is usually repetitive
TION [TROUBLESHOOTING HINTS]
@ Air/Fuel mixture too lean
@ Misfire
3 Poor connection in wiring harness
SYSTEM SELECT:
1 “88” flashes
Check ECU terminal 1F voltage CT= page F-150
Specification: Battery voltage
(Ignition switch ON)
+ If OK, replace ECU w page F-149 4 If not OK, check wiring between
ECU and Self-Diagnosis Checker
check sequence) w page F-106
heck ECU terminal ID voltage CT page F-150
oxygen sensor
F-59
Page 327 of 1164
![MAZDA PROTEGE 1992 Workshop Manual TROUBLESHOOTING GUIDE F
9 LACK OF POWER
_-- --
L L -
ESCRIP- *Performance poor under load when throttle valve wide open
ION *Reduced maximum speed
* Idle condition normal
VtOUBLESHOOTlNG HINTS] MAZDA PROTEGE 1992 Workshop Manual TROUBLESHOOTING GUIDE F
9 LACK OF POWER
_-- --
L L -
ESCRIP- *Performance poor under load when throttle valve wide open
ION *Reduced maximum speed
* Idle condition normal
VtOUBLESHOOTlNG HINTS]](/manual-img/28/57077/w960_57077-326.png)
TROUBLESHOOTING GUIDE F
9 LACK OF POWER
_-- --
L L -
ESCRIP- *Performance poor under load when throttle valve wide open
ION *Reduced maximum speed
* Idle condition normal
VtOUBLESHOOTlNG HINTS]
) Factors other than engine malfunction
*Clutch slipping
* ATX slipping
l Brake dragging l Low tire pressure
l Incorrect We size l Overloaded
‘, Low intake air amount @ Air/Fuel mixture too lean
l Fuel line pressure decreases l Fuel injection malfunction
@ Poor ignition
@ Low engine compression
@ Alcohol blended fuel used
l Throttle valve not open fully
*Clogged intake air system
l Low tire pressure CY Section H
CY Section K
cz7 Section P
c7 Section Q
w page F-l 14
CT= page F-l 12
Checker with ignition switch ON
w page F-83
rminal 1F voltage CT page F-150
Specification: Battery voltage
(Ignition switch ON)
* If OK, replace ECU w page F-149
c3 If not OK, check wiring between
ECU and Self-Diagnosis Checker
Ignition timing (BTDC)
l BP DOHC : 9*-l lo l BP SOHC
: 4O-8O 4 If advances, go to next step
* If not advance, check ECU terminal
w page F-150
F-61