Suzuki WagonR+ RB310 Service Manual page 2385

6-26 ENGINE DIAGNOSIS
Condition
Engine hesitates
(Momentary lack of
response as
accelerator is
depressed.
Can occur at all
vehicle speeds.
Usually most severe
when first trying to
make vehicle move,
as from a stop sign.)
Surge
(Engine power
variation under
steady throttle or
cruise.
Feels like vehicle
speeds up and down
with no change in
accelerator pedal.)
Excessive
detonation
(Engine makes
continuously
sharp metallic
knocks that change
with throttle opening.
Sounds like pop corn
popping.)
Possible Cause
Ignition system out of order
D Spark plug faulty or plug gap out of adjustment
D Leaky high-tension cord
Fuel system out of order
D Fuel pressure out of specification
Engine and emission control system out of
order
D Malfunctioning EGR valve (if equipped)
D Poor performance of TP sensor, ECT sensor or
MAP sensor
D Faulty fuel injector
D Faulty ECM
Engine overheating
Low compression
Ignition system out of order
D Leaky or loosely connected high-tension cord
D Faulty spark plug (excess carbon deposits,
improper gap, and burned electrodes, etc.)
Fuel system out of order
D Variable fuel pressure
D Kinky or damaged fuel hose and lines
D Faulty fuel pump (clogged fuel filter)
Engine and emission control system out of
order
D Malfunctioning EGR valve
D Poor performance of MAP sensor
D Faulty fuel injector
D Faulty ECM
Engine overheating
Ignition system out of order
D Faulty spark plug
D Loose connection of high-tension cord
Fuel system out of order
D Clogged fuel filter (faulty fuel pump) or fuel lines
D Air inhaling from intake manifold or throttle body
gasket
Engine and emission control system out of
order
D Malfunctioning EGR valve (if equipped)
D Poor performance of knock sensor, ECT sensor
or MAP sensor
D Faulty fuel injector(s).
D Faulty ECM
D Excessive combustion chamber deposits
Referring Item
Spark plugs in Section 6F1
High-tension cords in Section 6F1
Diagnostic Flow Table B-3
Trouble diagnosis in Section 6
EGR system in section 6E
TP sensor, ECT sensor or MAP
sensor in Section 6E
Diagnostic Flow Table B-1
Refer to "Overheating" section
Previously outlined
High-tension cords in Section 6F1
Spark plugs in Section 6F1
Diagnostic Flow Table B-3
EGR system in Section 6E
MAP sensor in Section 6E
Diagnostic Flow Table B-1
Refer to "Overheating" section
Spark plugs in Section 6F1
High-tension cords in Section 6F1
Diagnostic Flow Table B-1 or B-2
Trouble diagnosis in Section 6
EGR system in Section 6E
Knock sensor in Section 6, ECT
sensor or MAP sensor in Section
6E
Diagnostic Flow Table B-1
Piston and cylinder head cleaning
in Section 6A1