Suzuki 2000 Grand Vitara SQ625 Service Manual page 145

6-1-34 ENGINE (H25 ENGINE)
Condition
Improper engine
idling or engine fails
to idle
Engine hesitates
(Momentary lack of
response as the
accelerator is
depressed.
Can occur at all
vehicle speeds.
Usually most severe
when first trying to
make the vehicle move,
as from a stop sign.)
Possible Cause
Ignition system out of order.
D Faulty spark plug
D Faulty ignition coil with ignitor
Fuel system out of order.
D Fuel pressure out of specification
Engine overheating.
Engine and emission control system
out of order.
D Maladjusted TP sensor installation
angle if adjustable
D Faulty idle air control system
D Faulty evaporative emission control
system
D Faulty EGR system
D Faulty injector
D Faulty ECT sensor, TP sensor or
MAF sensor
D Faulty ECM (PCM)
Low compression
Others
D Malfunctioning PCV valve
Ignition System out of order.
D Spark plug faulty or plug gap as out of
adjustment
Fuel system out of order.
D Fuel pressure out of specification
– Clogged fuel filter
– Faulty fuel pressure regulator
D Clogged fuel filter, hose or pipe
Engine overheating
Engine and emission control system out
of order.
D Faulty EGR system
D Faulty injector
D Faulty TP sensor, ECT sensor or MAF
sensor
D Faulty ECM (PCM)
Low compression
Reference Item
Spark plugs in Ignition System
section.
Ignition coil in Ignition System
section.
Diag. Flow Table B-3 in this section.
Refer to "Overheating" section.
TP sensor in Engine and Emission
Control System section.
DTC P0505 Diag. Flow Table in this
section.
EVAP control system in Engine and
Emission Control System section.
DTC P0400 Diag. Flow Table in this
section.
Fuel injection in Engine and Emission
Control System section.
ECT sensor, TP sensor or MAF
sensor in Engine and Emission
Control System section.
Inspection of ECM (PCM) and its
circuit in this section.
Previously outlined.
PCV system inspection in Engine and
Emission Control System section.
Spark plugs in Ignition System
section.
Diag. Flow Table B-3 in this section.
Refer to "Overheating" section.
DTC P0440 Diag. Flow Table in this
section.
Fuel injector in Engine and Emission
Control System section.
TP sensor, ECT sensor or MAF
sensor in Engine and Emission
Control System section.
Inspection of ECM (PCM) and its
circuit in this section.
Previously outlined.