Mazda RX8 - No.8 Engine Runs Rough;Rolling Idle

NO.8 ENGINE RUNS ROUGH/ROLLING IDLE
8 ENGINE RUNS ROUGH/ROLLING IDLE
DESCRIPTION
• The engine speed fluctuates between the specified idle speed and a lower speed, and
the engine shakes excessively.
• The idle speed is too slow and the engine shakes excessively.
POSSIBLE
CAUSE
• Vacuum leakage
• Air leakage from intake-air system parts
• Air suction at intake-air system (between MAF sensor and intake ports)
• Air cleaner restriction
• Air cleaner improper installation
• Improper operation of drive-by-wire control system (abnormal signals from APP
sensor, TP sensor and load signal to PCM)
• SSV stuck open
• SSV solenoid valve malfunction (stuck open)
• APV stuck open*
• APV motor malfunction*
• Carbon or foreign materials on primary intake port
• APV position sensor malfunction*
• Poor fuel quality
• Inadequate fuel pressure
• Pressure regulator (integrated in fuel pump unit) malfunction
• Fuel pump body mechanical malfunction
• Fuel line restriction or clogging
• Fuel leakage from fuel injector
• Fuel injector (FP1) (RP1) malfunction (leakage, clogging, improper injector amount)
• Jet air mixing system malfunction (restriction or leakage in air passage)
• Restriction in exhaust system
• Improper operation of AIR system
• Purge solenoid valve malfunction (stuck open)
• Improper fuel injection control operation (abnormal signals from MAF, ECT and
IAT sensors to PCM)
• Erratic signal from eccentric shaft position sensor
• Damaged or improper installed eccentric shaft position sensor pulse wheel
• Disconnected electrical connectors
• Improper load signal input
• Engine overheating
• Low engine compression
! Engine internal malfunction
! Abnormal engine oil condition (viscosity, deterioration)
! Low oil pressure
! Excessive fuel pressure
! Air mixed in oil line
(w) RX8-Engine Troubleshooting
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