Suzuki GA413, Service Manual

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6-26 ENGINE GENERAL INFORMATION AND DIAGNOSIS
GA413
supple
Condition Possible Cause Reference Item
Engine hesitates
(Momentary lack of re-
sponse as the accelera-
tor is depressed.
Can occur at all vehicle
speeds.
Usually most severe
when first trying to make
the vehicle move, as
from a stop sign.)
Ignition system out of order
D
Faulty ignition coil or high-tension cords
Engine overheating
Engine and emission control system out
of order.
D
Fuel pressure out of specification
D
Faulty injector
D
Faulty TP sensor, ECT sensor or MAP
sensor
D
Faulty ECM
D
Malfunctioning EGR valve (if equipped)
Low compression
Diagnosis in Section 6F.
Refer to “Overheating” of this table.
Diagnostic Flow Table B-3
Diagnostic Flow Table B-1
TP sensor, ECT sensor or MAP sensor
in Section 6E.
Inspection of ECM and its circuit in Sec-
tion 6E.
EGR system in Section 6E.
Previously outlined.
Surges
(Engine power variation
under steady throttle or
cruise.
Feels like the vehicle
speeds up and down
with no change in the
accelerator pedal.)
Ignition system out of order
D
Faulty ignition coil or high-tension cord
Engine and emission control system out
of order.
D
Variable fuel pressure
D
Faulty MAP sensor (if equipped)
D
Faulty injector
D
Faulty ECM
D
Malfunctioning EGR valve (if equipped)
Diagnosis in Section 6F.
Diagnostic Flow Table B-3
MAP sensor in Section 6E.
Diagnostic Flow Table B-1
Inspection of ECM and its circuit in
Section 6E.
EGR system in Section 6E.
Excessive detonation
(The engine makes
sharp metallic knocks
that change with throttle
opening.
Sounds like pop corn
popping.)
Engine overheating
Ignition system out of order.
D
Faulty spark plug
Engine and emission control system out
of order.
D
Clogged fuel filter and fuel lines
D
Malfunctioning EGR valve (if equipped)
Refer to “Overheating” of this table.
Spark plugs in Section 6F.
Diagnostic Flow Table B-3
EGR system in Section 6E
D
Malfunctioning EGR valve (if equi ed)
D
Poor performance of ECT sensor or MAP
sensor
D
Faulty injector
D
Faulty ECM
Others
D
Excessive combustion chamber deposits
EGR system in Section 6E.
ECT sensor or MAP sensor in Section
6E.
Diagnostic Flow Table B-1
Inspection of ECM and its circuit in
Section 6E.
Piston and cylinder head in Section 6A.