Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 165

TROUBLESHOOTING - Symptom Chart
SYMPTOM
POSSIBLE CAUS E
SYSTEM
COMPONENT PART TYPE OF TROUBLE
Fuel pump
Drop in flow volum e
l t F
Injectors
Drop in injection volum e
e m ue sys
Pressure regulator
Fuel pressure too low
Fuel filter, fuel line
Clogge d
Igniter
Malfunctionin g
Hesitate s
during
Ignition system
Ignition coil
(poor contact )
acceleration
Spark plugs
Misfire
Manifold pressure
sensor (vacuum sensor)
e or resistanc e Volta
Electronic control
Water temp. sensor
g
are incorrect, open o r
system
Intake air temp . sensor
sho
rt
circui t
Thro
tt
le position senso r
Oxygen (02) sensor Malfunctionin g
Fuel pump Drop in flow volum e
l
F t
Injectors
Drop in injection volum e
e m
ue sys
Pressure regulator
Fuel pressure too lo w
Poor drivability
Fuel filter, fuel line Clogged
Igniter
Malfunctionin g
Ignition system Ignition coil
(poor contact )
Backfiring Spark plugs
Misfire
Manifold pressure
sensor (vacuum sensor)
Electronic control
Water temp . sensor
Voltage or resistance
system
Intake air temp . sensor
are incorrect
Thro
tt
le position senso r
Oxygen (02) sensor Malfunctionin g
Fuel system
Injectors Leakag e
Cold sta
rt
system
Cold sta
rt
injector
Leakage, inject s
continuousl y
Sta rt injector time SW
Stays on continuousl y
Afterfirin g
(muffler
Manifold pressure
sensor (vacuum sensor)
Voltage or resistanc e
explosions)
Electronic control
Water temp . sensor
are incorrect
system
Intake air temp . senso r
Thro
tt
le position sensor
Idle
contact won't go o n
Oxygen (02) sensor Malfunctioning
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