ignition MAZDA PROTEGE 1992 Repair Manual

F TROUBLESHOOTING GUIDE
10
ROUGH IDLE/ENGINE STALLS AT IDLE - AFTER WARM-UP
DESCRIP-
rlON
*Engine runs normally at idle during warm-up but engine stalls or vibrates excessively after warm-up [TROUBLESHOOTING HINTS]
3 Idle speed control system malfunction @ Air/Fuel mixture too rich
3 Air/Fuel mixture too lean l Fuel injection control malfunction l Air leakage (Correction for coolant temperature)
*Low fuel line pressure @ Poor ignition
@ Low engine compression CT= page F-83
Check ECU terminal 1F voltage CT page F-150
Specification: Battery voltage
(Ignition switch ON)
* If OK, replace ECU w page F-149 * If not OK, check wiring between
ECU and Self-Diagnosis Checker
Check for cause LY page F-151
Vacuum: More than 450 mmHg (17.7 inHg)
I.:.F page F-109
F-46

TROUBLESHOOTING GUIDE F
Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm’, 36-46 psi)
(Vacuum hose to pressure regulator Ine pressure while pinching
d If fuel line pressure quickly in-
creases, check pressure regulator w page F-129
* If fuel line pressure gradually in-
If not clogged, check fuel pump
maximum pressure w page F-126
Ignition timing (BTDC)
l BP DOHC : go-1 1 o l BP SOHC : 4”-6O
Resistance: 12-l 60
eck wiring between ECU
Engine compression (Minimum):
l BP SOHC :
634 kPa (6.5 kg/cm2, 121 psi)900 rpm
check distributor cap and
23UOFX-02
F-47

F TROUBLESHOOTING GUIDE
11 ROUGH IDLE/ENGINE STALLS AT IDLE - WHEN A/C, P/S, OR E/L ON
DESCRIP.
*Engine stalls or vibrates excessively at idle when A/C, P/S, or E/L ON TION *A/C, P/S, daytime running lights (Canada), headlights, blower fan and electric cooling fan operate normally
*Idle condition is normal when A/C, P/S, and E/L is OFF (TROUBLESHOOTING HINTS]
@ Idle speed control system malfunction l Engine speed feedback control inoperative ;TEP INSPECTION
ACTION
1
Check if “00” is displayed on Self-Diagnosis Yes
Checker with ignition switch ON Go to next step 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
W:SELFTEST
Check ECU terminal 1 F voltage w 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
2 Check switches for correct operation by Self-
Yes
Diagnosis Checker Monitor Lamp with ignition Go to next step
switch ON CT page F-105
No Lamp not ON or OFF with specltied
switch
Check for cause (Refer to specified
check sequence) w page F-108
Lamp always ON
Check wiring between ECU terminal ID
and Self-Diagnosis Checker
W:SELFTEST
3
EhFKk if ECU terminal IK (MTX) II (ATX) voltage
Yes Try known good ECU and check if con-
dition improves w page F-150 w page F-149
Specification: Battery voltage (at Idle)
1 K (LGIY)
No
Check for short circuit in wiring be-
tween diagnosis connector terminal
TEN and ground
23UOFX-02
-’
F-48

TROUBLESHOOTING GUIDE F
12 ROUGH IDLE/ENGINE STALLS JUST AFTER STARTING
DESCRIP-
*Engine starts normally but vibrates excessively or stalls just after starting (acceleration from idle) TION
*Idle conditions are normal in the other conditions [TROUBLESHOOTING HINTS]
@ Fuel injection control system or idle speed control sys-
@ Idle speed misadjustment
tern malfunction @ Ignition timing misadjustment
*Start signal not input to ECU iTEl
-s-- 3
4
5 INSPECTION
-T- ACTION
Check if “00” is displayed on Self-Diagnosis
Checker with ignition switch ON w page F-82
SYSTEM,SELECT: I
r -SELECT SW: A
Check if ECU terminal voltages are OK
MTX...Especially 1 N
ATX... Especially 1T w page F-150
Connect System Selector to diagnosis connector
and set Test Switch to “SELF TEST” and check
for correct ignition timing at idle after warm-up w page F-78
Ignition timing (BTDC)
l BP DOHC : 9”-11 o l BP SOHC : 4O--6O
l B8 : 60-80
Check continuity between throttle sensor termi-
nals IDL and E CT page F-159
MTX
Clearance between throttle
lever and stopper
MTX O.lmm (0.004 in)
1 .Omm (0.039 in)
ATX 0.1 mm (0.004 in)
0.6mm (0.024 in) Continuity
Yes
No
Yes
No
Try known good ECU and check if condition
mproves w page F-149 Yes
No
Yes
Go to next step No
Check for cause Yes
In same condition as Step 3 inspection
and apply parking brake
Check for correct idle speed w page F-80
Idle speed: 700-800 rpm
No
Adjust Yes
Go to next step No
Adjust Go to next step Service Code No. displayed
Check for cause (Refer to specified
check sequence) w page F-83
“88” flashes
Check ECU terminal IF voltage w page F-150
Specification: Battery voltage
(Ignition switch ON)
d If OK, replace ECU w page F-149
* If not OK, check wiring between
ECU and Self-Diagnosis Checker c7 page F-151
3 If OK, go to next step
3 If not OK, adjust idle speed w page F-80
w page F-79
w page F-159
F-49

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

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

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

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

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

TROUBLESHOOTING GUIDE
TEP INSPECTION
ACTION
7 Check for correct fuel line pressure at idle Yes Check if fuel line pressure decreases w page F-129 when accelerating quickly Fuel line pressure:
c3 If decreases, check fuel line and fil- 265-314 kPa (2.7-3.2 kg/cm’, 38-46 psi) ter for clogging (Vacuum hose to pressure regulator dis- *
If no decrease, go to next step connected)
INSTALL CLAMPS No Low pressure
Check fuel line pressure while pinching
fuel return hose
+ If fuel line pressure quickly in-
creases, check pressure regulator w page F-129
+ If fuel line pressure gradually in-
creases, check for clogging be-
tween fuel pump and pressure
regulator
If not clogged, check fuel pump .*
maximum pressure w page F-126
8 Connect System Selector to diagnosis connector Yes Check if ignition timing advances when
and set Test Switch to “SELF TEST” and check accelerating
for correct ignition timing at idle after warm-up w page F-79
c3 If advances, go to next step
c3 If not advance, replace ECU w page F-149
Ignition timing (BTDC)
l BP DOHC : go-1 1 o l BP SOHC : 4’-8’
l B6 : 6O--8O No Adjust w page F-79
9
Check if air duct and air hoses are correctly Yes Go to next step
installed w page F-109
No
Repair
10 Check if exhaust system is restricted Yes Repair or replace w page F-136
No SOHC
Go to Step 12 DOHC
Go to next step
11 Check if variable inertia control system (VICS) is
Yes Go to next step
OK w page F-118
No
Repair or replace
12 Try known good ECU and check if condition
improves w page F-149
-’
F-58