Suzuki 2006 SX4 Service Manual page 96

1A-52 Engine General Information and Diagnosis:
Condition
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
Faulty spark plug (excess carbon
deposits, improper gap, burned
electrodes, etc.)
Variable fuel pressure
Kinky or damaged fuel hose and lines
Faulty fuel pump (clogged fuel filter)
Poor performance of MAF sensor
Faulty fuel injector
Faulty ECM
Faulty electric throttle body assembly
Faulty APP sensor assembly
Faulty spark plug
Engine overheating
Clogged fuel filter (faulty fuel pump) or
fuel lines
Air drawn in through intake manifold or
throttle body gasket
Poor performance of knock sensor, ECT
sensor or MAF sensor
Faulty fuel injector(s)
Faulty ECM
Excessive combustion chamber
deposits
Fuel pressure out of specification
– Dirty fuel filter
– Dirty or clogged fuel hose or pipe
– Faulty fuel pressure regulator
– Faulty fuel pump
Correction / Reference Item
"Spark Plug Inspection in Section 1H"
"Fuel Pressure Check"
"Fuel Pressure Check"
"Fuel Pump and Its Circuit Check"
"Mass Air Flow (MAF) and Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C"
"Fuel Injector Circuit Check"
"Inspection of ECM and Its Circuits"
"Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C"
"Accelerator Pedal Position (APP) Sensor
Assembly Inspection in Section 1C"
"Spark Plug Inspection in Section 1H"
Condition "Engine overheating"
"Fuel Pressure Check" or "Fuel Pump and Its
Circuit Check"
Check air intake system.
"DTC P0327 / P0328: Knock Sensor Circuit
Low / High", "Engine Coolant Temperature
(ECT) Sensor Inspection in Section 1C" or
"Mass Air Flow (MAF) and Intake Air
Temperature (IAT) Sensor Inspection in
Section 1C"
"Fuel Injector Circuit Check"
"Inspection of ECM and Its Circuits"
"Cylinder Head Inspection in Section 1D" and
"Pistons, Piston Rings, Connecting Rods and
Cylinders Inspection and Cleaning in Section
1D"
Refer to "Fuel Pressure Check".