NO.8 ENGINE RUNS ROUGH/ROLLING IDLE [MZI-3.7]
NO.8 ENGINE RUNS ROUGH/ROLLING IDLE (MZI-3.7) DETECTION CONDITIONS AND
POSSIBLE CAUSES
8
ENGINE RUNS ROUGH/ROLLING IDLE
DESCRIPTION
z
Engine speed fluctuates between specified idle speed and lower speed and
engine shakes excessively.
z
Idle speed is too slow and engine shakes excessively.
POSSIBLE
CAUSE
z
Air leakage from intake-air system parts
z
A/C system operation is improper
z
Erratic signal to ignition coil
z
Spark plug malfunction
z
Purge solenoid valve malfunction
z
Improper operation of electronic throttle control system
z
Idle learning of electronic throttle control system is not completed
z
Erratic or no signal from CMP sensor
z
Low engine compression
z
Improper valve timing
z
Improper variable valve timing control system operation
z
Erratic signal from CKP sensor
z
Improper air / fuel mixture ratio control operation (abnormal signal form MAF
sensor or HO2S)
z
Open or short circuit in PCM GND circuit
z
Poor fuel quality
z
PCV valve malfunction
z
Air cleaner restriction
z
Restriction in exhaust system
z
Disconnected electrical connectors
z
Inadequate fuel pressure
z
Fuel pump body mechanical malfunction
z
Improper load signal input
z
Fuel line restriction or clogging
z
Improper fuel injection control operation
z
Fuel leakage from fuel injector
z
Fuel injector clogging
z
Engine overheating
z
Vacuum leakage
z
Pressure regulator malfunction (built-in fuel pump unit)
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:10:05 AM
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