1992 MAZDA PROTEGE fuel pressure

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

TROUBLESHOOTING GUIDE F
TEPt INSPECTION ACTION
Fuel line pressure:
More than 147 kPa (1.5 kg/cm*, 21 psi)
w page F-125
4 If OK, check injector for fuel
w page F-132
w page F-127
w page F-158
+ If OK check connections of water
osensor and ECU 2Q terminal
check connections of water
osensor and ECU 2E terminal
K, replace water ther-
w page F-83
w page F-150
Specification: Battery voltage
(Ignition switch ON)
Q If OK, replace ECU CT page F-149
+ If not OK, check wiring between
ECU and Self-Diagnosis Checker
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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

TROUBLESHOOTING GUIDE F
1TEP INSPECTION
ACTION
7 Connect diagnosis connector terminals F/P and Yes
Go to next step
GND with jumper wire and check for correct fuel
line pressure with ignition switch ON w page F-122
No Low pressure
Check fuel line pressure while pinching Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm*, 38-46 psi) fuel return hose
c3 If fuel line pressure quickly in-
creases, check pressure regulator w page F-129
+ If fuel line pressure gradually in-
creases, check fuel line for clog-
ging between fuel pump and
pressure regulator
If not clogged, check fuel pump
maximum pressure High pressure w page F-126
Check if fuel return hose is clogged or
restricted
INSTALL CLAMPS c3 If OK, replace pressure regulator w page F-130 c3 If not OK, repair or replace hose
8
Try known good ECU and check if condition
Yes Replace ECU w page F-149
improves w page F-149 No
Change fuel to another brand
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F TROUBLESHOOTING GUIDE
7 CRANKS NORMALLY BUT HARD TO START - AFTER WARM-UP
*Engine cranks at normal speed but requires excessive cranking time before starting after running and hot
DESCRIP- soaked
TION *Battery in normal condition
*Engine starts normally when cold
*Engine runs normally at idle [If idle condition not OK, refer to “Rough idle” (Nos. 8-12)] [TROUBLESHOOTING HINTS]
3 Air/Fuel mixture too rich
@ Vapor lock l Fuel injection control malfunction
*Fuel pressure not held in fuel line after engine stopped l Injector fuel leakage
*High RVP (winter) fuel used in warm weather
l Pressure regulator control system malfunction [BP] w page F-150
Specification: Battery voltage
(Ignition switch ON)
W: SELF TEST c3 If OK, replace ECU w page F-149 * If not OK, check wiring between CT- page F-134
Fuel line pressure: More than 147 kPa
(1.5 kg/cm*, 21 psi) for 5 min. w page F-130
+ If OK, replace pressure regulator CT- page F-130
c3 If not OK, check fuel pump hold w page F-125
If fuel pump is OK, check injectors
for fuel leakage (3 page F-132
F-40

F TROUBLESHOOTING GUIDE
8 ROUGH IDLE/ENGINE STALLS AT IDLE - ALWAYS
bESCRIP- l Engine starts normally but stalls or vibrates excessively at idle in every condition
‘ION TROUBLESHOOTING HINTS]
D Air/Fuel mixture too lean @ Incorrect idle speed
l Air leakage l Idle speed misadjustment l Fuel injection control malfunction l Idle speed control malfunction
*Low fuel line pressure @ One or more spark plugs not firing
3 One or more injectors clogged or not operating @ Low engine compression
3 Low intake air amount @ Airflow meter stuck INSPECTION
1
1
2
3
4
5
6
- Check if “00” is displayed on Self-Diagnosis
Checker with ignition switch ON w page F-82
SYSTEM2ELECT: 1
M v’SELECT SW: A TEST
Check if ECU terminal voltages are OK
MTX...Especially 2D, 20 and 2Q
ATX... Especially 2B, 2E and 3D CT page F-150
Disconnect high-tension lead at idle and check if
engine speed decreases equally at each cylinder
Check for injector operating sound at idle
Check if battery voltage exists at injector connec-
tor (W/R) wire
Check if strong blue spark is visible at discon-
nected high-tension lead
, Yes No Service Code No. displayed
Check for cause (Refer to specified
:heck sequence) “88” flashes
Check ECU terminal IF voltage CT page F-150
Specification: Battery voltage
(Ignition switch ON)
3 If OK, replace ECU w page F-149 3 If not OK, check wiring between
ECU and Self-Diaanosis Checker Yes
Go to next step No
Check for cause Yes
Go to Step 8 No
Go to next step
Go to Step 6
Go to Step 5 Yes
No
Yes
No
Yes
No I-
30 to next step w page F-83
0 page F-151
Check if injector resistance is OK c7 page F-131
Resistance: Approx. 12-l 852
c3 If OK, check wiring between ECU
and injector
c3 If not OK, replace injector w page F-131
Check wiring between ECU and injector
Go to next step
Check high-tension lead w page G-17
Q If OK, check distributor cap and
rotor w page G-22
c3 If not OK, replace high-tension lead
F-42

TROUBLESHOOTING GUIDE F
WEAR AND CA
DAMAGE AND
DETERIORATION
r;f> If OK, replace injector
=D If not OK, check for cause w page F-131
u page Bl-10
82-l 0
Fuel line pressure:
265-314 kPa (2.7-3.2 kg/cm2, 38-48 psi) fuel line pressure while pinching
* If fuel line pressure quickly in-
creases, check pressure regulator L-Y page F-129
~3 If fuel line pressure gradually in-
creases, check for clogging be-
tween fuel pump and pressure
maximum pressure
CT page F-126
airflow meter moves smoot
_, .’
No Go to next step
I1
Check for correct engine compression
Yes Go to next step
CI page 81-10
82-l 0
Engine compression (Minimum):
l BP SOHC
834 kPa (8.5 kg/cm*, 121 psi)300 rpm
l BP DOHC
883 kPa (9.0 kg/cm*, 128 psi)-300 rpm
l B6 No Check for cause
CT page 81-10
82-l 0
932 kPa (9.5 kg/cm*, 135 psi)-300 rpm
I2 Connect System Selector to diagnosis connector
Yes Try known good ECU and check if con-
and set Test Switch to “SELF TEST” and check
dition improves
CT page F-149
for correct ignition timing at idle after warm-up
CT page F-79
Ignition timing (BTDC)
BP DOHC : Q”-ll”
BP SOHC : 4O-6O
B6
: 6”--8* No Adjust ignition timing
a- page F-79
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