1992 MAZDA 323 fuel pump

TRUU8LESH00TlNG GUIDE F3
13EOF3-328
13EOF3-329
1
PRECAUTIONS
Fuel Pressure Release and Servicing Fuel System
Fuel
in the fuel system remains under high pressure when the engine is not running.
a) Before disconnecting any fuel line, release the fuel pres-
sure from the fuel system to reduce the possibility of injury
or fire as discribed below.
1. Start the engine.
2. Push the rear seat cushion buttons and remove the
cushion.
3. Disconnect the fuel pump connector.
4. After the engine stalls, turn off the ignition switch.
5. Reconnect the fuet pump connector and install the rear
seat cushion.
b) Use a rag as protection from fuel spray when disconnect-
ing the fuel hoses.
Plug the hoses after removal.
c) When inspecting the fuel system, use a suitable fuel pres-
sure gauge.
Caution
l install hose clamps to secure the fuet pressure
gauge to the fuei fitter and the fuel main hose to pre-
vent fuel leakage.
Pinching Hose
When pinching an air hose-or a fuel hose with pliers, wrap
the hose with a rag to prevent damage,
F3-2 t

F3 TROUBLESHOOTING GUIDE
SYMPTOM TROUSLESHOOTING
2 . CRANKS NORMALLY BUT WILL NOT START (NO COMBUSTION)
LIESCRIP-
l Engine cranks at normal speed but shows no sign of firing l Battery in normal condition
TION *Throttle valve not held fufly open while cranking (dechoke system not operating}
l Fuel in tank
UROOBLESHUOTlNG HINTS]
@ No spark
@.I low fuei tine pressure
l Ignition control malfunction @I Low engine compresslon l Ignition system component malfunction
@ No fuel injection
l Fuel pump inoperative l Ihjectors inoperative
;TEP
INSPECTION
I ACTION
1
Is strong btue spark visible at disconnected high- Yes Go to Step 3
tension lead?
NO Go to Step 2
2 Is “00” dlsplayed on Self-Dlagnosjs Checker
Yes
with ignltron switch ON? Check rgnltion system (Refer to
Troubleshooting “Misfire”)
c7 Section G
SYSTEM SELECT: 1 No
Service Code No. displayed Check for cause (Refer to specified
check sequence)
G- page
F3-16
“66” flashes
Check ECU termrnal 1F voltage
3 page W-45

Voltage: Battery vabage
(ignition switch ON)
W: SELF TEST C+ If OK, replace ECU
4 If not OK, check wiring
CT page F3-2
(ECU
- Self-Diagnosis Checker)
3
Connect diagnosis connector terminals F/P and
Yes
GND with jumper wire; IS fuel pump operating Does engine start in this condition?
sound heard wjth ignition switch ON?
4 If it does, check circuit-opening
relay
4 If it does not, go to Step 5
No Go to next step
F3-22
iTEF
6
8

TROUBLESHOOTING GUlDE F3
STEP INSPECTION ACTlON
4
Is there buttery voltage at fuel pump connector Yes
* (G/R) with lgnitron switch ON and F/P terminal Check contmurty of fuel pump
between termrnafs G/R and 8
Check ctrcutt openmg relay
5
Is qector operating sound heard whtle engine IS Yes Go to Step 8
being cranked?
No Go to next step
CcI page F3-45
+ If 0K;check for a short cjrcult rn
wiring harness
(Injector reastor-Injector)
=D If not OK, replace Injector reststor
fuel Line pressure: 265-314 kPa
12.7-3.2 kgflcd, 38-46
psi)
if fuel return hose is clogged or
t, replace pressure
CT psge F3-3
F3-2 3

TROUBLESHOOTING GUIDE F3
4 CRANKS NORMALLY 8UT WILL NOT START (PARTfAL COMBUSTION) - AFTER WARM-UP
&RIP-
l Engine cranks at nurmal speed and shows partial combustion but will not Continue running after being hot
soaked
FION
l Battery in normal condltlon
*Engine starts normally when cold
TROUBLESHOOTING
HINTS] 3 Air/Fuel mixture too rich @ Vaporlock
ssure not held in fuel line after engrne IS
GND mth jumper wire tor 3
minutes with ignition
Fuel
line pressure: 265-314 kPs (2.7-3.2 kgflcm2, 38-46 psi 1
c3 If pressure
quickly increases,
check pressure regulator
4 If pressure
gradually increases,
check fuel line and filter lor
clogging
If hose is not clogged. check fuel
pump maximum pressure
High pressure Check if fuel return hose is clogged or
restricted
INSTALL CLAMPS e If rt is not, replace pressure
regulator
@ It It 6. repalr or replace it CT page F3-3
F3-25

F3 TROUBLESHOOTING GUIDE
I- STEP lNSPECTlON ACTION
Yes Go to Step 8
5 In same condition as in Step 2, IS fuel ilne pres-
sfire held after Igrxtbon swatch rs turned OFF?
Fuel line pressure: More than 147 kPa
Il.5 kgflcm’, 21 Psi 1 for 5 min.
6 In same condition as in Step 3, IS fuel line pres-
sure held after lgnltron switch IS turned OFF?
Fuel line pressure: More than 147 kPa
{ t.5 kgf/cm*, 21 psi) for 5 min.
No
I Go to next step
Plug both vcuum ports of pressure regulator; IS
fuel lme pressure held after ignltlon switch is
turned OFF? Yes Replace pressure regulator
r~ page F3-3
Fuel line pressure: More than 147 kPa
{ 1.5 kgf/crn*, 21 psi] for 5 min.
NO Check fuel pump hold pressure
e If OK, check InJector for fuel
leakage
e If not OK reptace fuel pump ZF- page F3-42
T page F3-3
8 Dlscofinect water thermosensor connector, does
engtne start? Yes Check water thermosensor
e ff OK. check connectrons of water
thermosensor and ECU 2Q terminal
Q If not OK, replace water thermo-
sensor
ET page F3-13
No 1 Go to next step --~
Is “00” drsplayea on Self-Diagnosis Checker
with ignition switch ON? 9 Yes Go to next step
NO Service Code No. displayed
Check for cause (Refer to specified
check sequence)
c7 page F3-16 SYSTEM SELECT, 1
“88” flashes
Check ECU terminal IF voltage
KIT page F3-45
Voltage: Battery voltage
(ignition switch ON)
e If OK, replace ECU
ET- page F3-2
e If not OK, check wiring
(ECU - Self-Diagnosis Checker)
Y %EtECT SW: A
Yes 1 Go to next step 10 Are rf ECU termrnaf voltages are OK?
(especjaffy 1C. 2D. and 2Q)
CT page F3-45
NO Check for cause
Yes Replace ECU
=T page F3-2
No Change to another brand of fuel
13EOF3 331 Try known good ECU, does condition improve?
CT page F3-2
F3-26

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

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

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.