1992 MAZDA 323 fuel pressure

TROUBLESHOOTING GUlDE F3
7 CRANKS NORMALLY BUT HARD TO START - AFTER WARM-UP
*
l Engrne cranks at normal speed but requkres excessive cranking time before starting after running and being
DESCRIP- hot soaked
TION
l Battery rn normal condition l Engine starts normatly when cold
*Engine runs normally at Idle (If idle condrtron is not OK, refer to “Rough idle” ~Nos. 8-l 21)
[ ~ROUBLESHOOTLNG HINTS1
[ i 5 ArrlFuel mixture too Rich - l Fuel rqection control malfunction l lnpector fuet leakage
I
TEP tNSPECTlON @ Vaporlock
l Fuel pressure not held rn fuel line after engrne IS
stopped
l Pressure regulator control system malfunction
I ACTION
1 Is “00” dispiayed on Self-Diagnoses
Checker wrth rgnrtron switch ON7
SYSTEM?_SELECT. 1
SELECT SW. A
Remove vacuum hose from pressure regulator
(port A) ancI plug rt. dOt?S engine start normally’-,
Remove both vacuum hoses from pressure regu-
lator (ports A and Bj and plug them; does en-
gine start normally7
@
PtUG
/ /
Are ECU terminal voltages OK
(especially 1 C, 20, 20 and 2T)?
w page F3-46 Yes Go to next step
No Service Code No. displayed
Check for cause (Refer to specified
check sequence) CT oaae F3-16
“88” flashes
Check ECU terminal 1F voltage
Voltage: Battery voltage
(ignition switch ON) w page F3-45
( cs> It OK. replace ECU
/ w page F3-2’
3 If not OK, check wlrtng
(ECU - Self-Dlagnosrs ChecKer)
Yes Check pressure regulator control sys-
.
tern (high temperature operation) w page F3-43
I NO Go to next step
Check pressure regulator control sys-
tem (low temperature operation)
No 1 Go to next step
Yes Go to next step
NO Check for cause
F3-27

F3 TROU8LESliOOTING GUIDE
iTEP INSPECTION
ACTtUN
5 Run engine at idle; is fuel line pressure held af-
Yes Go to next step
ter ignition switch is turned OFF?
Fuet Ijne pressure: More than 147 kPa No Plug both vacuum potts of pressure
{1,5 kgflcd, 21 pdf for 5 min. regulator;
and check if fuel line pres-
sure is held after ignition switch is
turned OFF
NSTAtl CLAMPS 4 If it is, replace pressure regulator
c3 If it is not, check fuel pump hold CT page F3-3
pressure
If fuel pump is OK, check injectors
for fuet leakage
CT- page F3-4
6 Warm up engine to normal operating tempera-
Yes
ture and stop it Change to another brand of fuel
Connect diagnosis connector terminals F/P and
GND with jumper wire for 3 minutes with rgnitlon
switch ON; does engine start easily?
No Go to next step
7 Try known good ECU; does condition improve?
Yes Replace ECU
CT page F3-3 w- page F3-3
No Change to another brand of fuel
t3EOF3
F3-28

TROUBLESHOOTING GUIDE F3
8
1 ROUGH IDLE/ENGINE STALLS AT IDLE - ALWAYS
DESCRtP- 1 l Engine starts normally but stalls or vibrates excessively at idle in every condition
TION
[TROUBLESHOOTiNG HlNTSJ @ Air/Fuel mixture tw lean @ Incorrect idle-speed l ldiespeed misadjustment l Idle-speed control malfunction
$I One or more spark plugs not firing
9 Low engine compression
B Airflow meter stuck l Air leakage l Fuel injection control malfunction
*Low fuel line pressure
@ One or more injectors clogged or not
@ Low intake air amount operating
INSPECTION
Is “00” displayed on Self-Diagnosis
Checker with ignition switch ON?
1
SYSTEM SELECT: 1
ACTION
Go to next step
Service Code No. displayed Check for cause (Refer to specified
check sequence) c7 page F3-16
“88” flashes
Check ECU terminal IF voltage
(17 page F345
--.
‘\.
Voltage: Battery v&age
(Ignition switch ON)
4 If UK, replace ECU IT page F3-2 c3 If not OK, check wiring
(ECU - Self-Diagnosis Checker) Y -SELECT SW: A
Are ECU terminal voltages OK
(especially 20, 20, and ZQ)?
D page F3-45 Yes
Gu to next step
NO Check for cause
Disconnect each high-tens&on lead at idle: does
engine speed decrease equally at each cylindeR Yes Go to Step 9
NO Go to next step
Is injector operating sound heard at idle? [ Yes Go to Step 7
t- NO Stop engine and go to next step
Yes Check if injector resistance is OK
CT page F3-41 Is there battery voltage at each injector connec-
tor (No.1 (P), No.2 (R), No.3 QV), No.4 (0)) with
ignition switch ON?
Resktance: Approx. 2.110
(at 20*C [68*F))
4 if it is, check wiring
(ECU - Injector)
c3 If it is not, replace itijector
Go to next step
NO
Is there battery v&age at injector resistor (W/R)
I .Yes
with ignition switch ON? Check mjeotor resistor
4 tf OK, check for short circuit in wir-
ing (Injector resistor-Injector)
e3 If not OK,’ replace injector resistor
Check for open circuit in wiring (Main
relay (FUEL INJ relay)-Injector resistor)
Go to next step
t NO 1
Is strong blue soark visible at each disconnected Yes
‘Check ‘high-tension lead
4 If UK. check distributor cap and
rotor .
c3 If not OK, replace high-tension lead
‘-F3-29

F3 TROUBLESHUOTING GUIDE
TEPI tNSPECTION ACflON
e If OK, replace injector
4 If not OK, check for cause w Section 82
(Upper vacuum hose to pressure regulator 4
If pressure quickly increases,
check pressure regulator
4 If pressure
gradually increases,
check for clogging between fuel
pump and pressure regulator
if hose is not clogged, check fuel
pump maximum pressure
I
12 Is engine compression correct? Yes Go to next step w Sectlon 82
Engine
compression: 1059 kPa (10.8 kgf/cm2, 152 psi]-300 rpm NO Check for cause w Section B2.
13 Connect System Selector to diagnosis connector
Yes Try known good ECU; does condition
and $et Test Switch to SELF TEST; is ignition improves? w page f3-3 timing correct at idle after warm-up?
ignition timing (BTDC): 10 * to
NO Adjust ignition timing
F3-30
7
*
10
DES&
HON
-*
ITEP
2
3
4

TROUSLESHOOTING GUIDE F3
10 ROUGH IDLE/ENGINE STALLS AT IDLE - AmER WARM-UP
DESCRIP- -Engine runs normalty at idle during warm-up but engine stalls or vibrates excessively after warm
TlO#
TROUBLESHOOTING HINTS]
3 Idle-speed control system malfunction
3 Air/Fuel mixture too lean
l Air leakage
*Low fuel line pressure
TEP
INSPECTION
1
ts “00” dlsplayed on Se\-Diagnosis Checker
with ignition switch ON?
SYSTEM SELECT: 1 @ Air/Fuel mixture too rich
l Fuel injection control malfunctlon
(correction for coolant tem$eratuie)
@ Poor ignition
@ Low engine compresslon
ACTION
YES Go to next step
No Service
Code No. displayed
Check for cause (Refer to specified
check sequence)
w page F3-16
“88” flashes Check ECU terminal IF voltage w page F345
Voltage: Battery voltage
(ignition switch ON)
W: SELF TEST e !f UK, replace ECU
w page F3-3 c3 ff not OK, check wiring
(ECU - Self-Diagnosis Checker)
2 Are ECU termrnal voltages OK Yes Go to next step
(especially 20, 20, and 2Q)?
w page F3-45 No
Check for cause
3 Disconnect each high-tension lead at idle; does Yes Go to next step
engine speed decrease equally at each cylinder?
NO Go to Step 9
4 Is intake manifold vacuum correct at idle? Yes Go to next step
Vacuum: More than 450 mmHg f 17.7 InHg )
NO Check for air leakage of intake air sys-
tem components
5 Is air cleaner element clean? Yes Go to next step
No Replace air cleaner element
F3-3 1

F3 TROUBLESHOOTING GUIDE
3TEI ACTION
Is fuel line pressure correct at Idle?
*
Fuel line pressure: 265-314 kPa
12.7-3.2 kgf/cm’, 38-46 psi]
(Two vacuums hose to pressure regulator
disconnected)
304-392 kPa [ 3.1-4.0 kgf/cm’, 44-57 psi 1
(Upper vacuum hose to pressure regulator
disconnected)
INSTALL CLAMPS Yes Go to next step
No Low pressure
Check fuel line pressure while pinching
fuel return hose
4 If pressure quickly Increases,
check pressure regulator
e If pressure gradually Increases,
check for clogging between fuel
pump and pressure regulator
If hose is not clogged, check fuel
pump maxrmum pressure
Connect System Selector to diagnosis connector
and set Test Switch to SELF TEST; is ignition
tlmlng at idle correct after warm-up?
Ignition timing (BTDC): 10 f lo Yes Go to next step
No Adjust tgnrtkon system
8 Dtsconnect water thermosensor connector; does
engine condrtlon Improve? Yes Replace water thermosensor
No
Try known good ECU. does condltlon
Improve?
w page F3-13
Go to next step
Check if injector resistance is OK
w page F3-42 9 Is jqector operating sound heard at Idle?
Yes
No
Resistance: Approx. 2.11 Q
(at 20°C 168*F])
4 If it is, check wlnng
(ECU - Injector)
c3 If it Is not, replace injector
Go to next step IO
Yes Is engine compressron cprrect?
w Section G
No
Engine compression:
1059 kPa 110.8 kgf/cm2, 152 psi)-300 rDm
is strong blue spark vrslble at each disconnected
hrgh-tension lead?’ Check engine
3 Section B2
17
Yes Go to next step
No Check high-tension lead
w Section G
c3 If UK, check distrrbutor cap and
rotor
3 If not OK, replace htgh-tensron lead
Try known good ‘ECU: does condrtron
Improve7
w page F3-3 12 Are spark plugs.OK?
w Section G
l Wear and carbon butld up l Piug gap l Damage Yes
NO
Clean, adjust
13EOi3.334
F3-32.

FUEL SYSTEM F3
13EOF3.34
c I 13EOF3-364 FUEL PUMP CONNECTOR
/
!NSTALL CLAMPS
I
l nspection
1, Disconnect the resistor/relay connector.
2. Ground the fuel pump resistor relay terminal D.
3. Apply battery voltage and check for continuity as shown.
Terminal C
Continuity between A and I3
Battery voltage applied NO
ov Yes
4. Measure the resistance between terminals E and F.
Resistance : 0.38--0.42Q (at 2O*C {6S°F 1)
PRESSURE REGULATOR
Inspection
Fuel line pressure
Warning
l Before performing the following operation, release
the fuel pressure from the fuel system to reduce the
possibility of injury or fire. (Refer to page F3-21.)
1. Disconnect the negative battery terminal.
2. Connect a fuel pressure gauge between the fuel filter and
the fuel main hose. (install clamps as shown.) , .
I
3. Connect the negative battery terminal.
/t.
4, Start the engine and run it at idle.
5. Measure the fuel line pressure.
Fuel line pressure:
206-255 kPa [ 2.1-2.6 kgflcml, 30-37 psi )
6. Disconnect the upper vacuum hose from the pressure regu-
lator and measure the fuel line pressure.
Fuel line pressure:
304-392 kPa (3.1-4.0 kgf/cm2, 44-57 psi )
F3-41

TO TECHNICAL DATA
FUEL AND EMISSION CONTROL SYSTEMS
Item.
Idle speed
tgf-don trrmng-
Fuel pump
MaxImum output pressure
Transfer pump
Maximum output pressure
Fuel filter Engine
rPm
BTDC
kPa [ kgf/cm2, psi 1 1
kPa { kgflcm2, PSI ) 1 BP OUHC turbo
800 f 50
10 l 10
490-736 (5.0-7.5, 71-1 IO]
39 10.4, 5.7 ) or higher
I Type
Low-pressure side Nylon element (in fuel pump)
Hiah-Dressure side PaDer element
Pressure regulator
Regulating low kPa ( kgflcm2, psr 1 265-314 (2.7-3.2, 38-46 1
pressure High kPa { kgflcm2, psr 1 304-392 (3.1-4.0, 44-57 1
lniector
_ Type Low-ohmic
Type of drive
Electromechanical
Resistance q
Approx. 2.11 Q (at 20% ( 68*f )]
lniector reslstor
L - Resistance/injector
Idle-speed control (tSC) valve
TvDe n 1 6 [at 20°C 168OFjj
I Rotarv
Resistance
Solenoid valve (purge control)
Resbstance
Solenoid valve {wastegate)
Resistance n(
R I
i-l I 1 t-13 [at ZO*C {68OF j]
23-27 tat 20°C l68OFll
. r.
33-39 lat 20°C I68OF 11
Solenoid valve (PRC)
Resistance Low temp. q
33-39 [at 2O*C {SS*F]]
High temp. 0 1 33-39 [at 20°C (68OF]]
Water thermosensor
-20°C ( -4OFJ 1 14.6-17.8
Resistance kQ 2o”c I 68OF) 2.21-2.69
40°C ( tO4OF) 1.0-l 3
80°C I176OFJ 0.29-0.35
Airflow meter
Resistance R E244Vs
E2*Vc Fuity closed
Fully open I 20-600
20- 1,000
200-400
EP++THAA
(intake air
thermosensor) -2O*C ( -4OFj 1 13,600-l 8,400
20% 1 68OF) 1 2,210-2,690
6O*C 114OOFl i 493-667
EI ~Fc
I Fully closed 00
0 1
Oxygen sensor (ceramic beater coil)
Resistance
Fuel tank Approx. 6 [at 20°C f68OF)]
I CaDacW L I US oal. ImD aal I I 60 I 15.9, 13.2 I
I
Air cleaner
Element type
Fuel
Specrficatioir Oil permeated
Unteaded premium (RON 95 or higher)
l TEN terminal of diagnosis connector grounded. .
-
ENGINE ELI
3attery
I
Dark current’
Alternator
Starter
Distributor qr
Ignition timin?
ffEN terminal
Ignition coil
Spark plug
l ’ Dark current
r2 Standard pl