Mazda RX8 - No.4 Hard to Start;Long Crank;Erratic Start;Erratic Crank

NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
DESCRIPTION
• The starter cranks engine at the normal speed but the engine requires excessive
cranking time before starting.
• The battery is in the normal condition.
POSSIBLE
CAUSE
• Vacuum leakage
• Air leakage from intake-air system
• Air suction at intake-air system (between MAF sensor and intake ports)
• Air cleaner restriction
• Improper operation of drive-by-wire control system
• Drive-by-wire control system operates in fail-safe mode
• Throttle body malfunction (stuck open)
• SSV stuck open
• SSV solenoid valve malfunction (stuck open)
• APV stuck open*
• APV motor malfunction*
• APV position sensor malfunction*
• Poor fuel quality
• Jet air mixing system malfunction (restriction or leakage in air passage)
• Inadequate fuel pressure
• Pressure regulator malfunction (integrated in fuel pump)
• Fuel injector (FP1) (RP1) is clogged.
• Open or short in fuel injector (FP1) (RP1) control signal circuit
• Restriction in exhaust system
• Purge solenoid valve malfunction (stuck open)
• Improper air/fuel ratio control (abnormal ECT signal to PCM)
• Erratic signal form eccentric shaft position sensor
• MAF sensor contamination (abnormal signal to PCM)
• MAF sensor improper installation
• Low engine compression
! Engine internal malfunction
! Abnormal engine oil condition (viscosity, deterioration)
! Low oil pressure
! Excessive fuel pressure
! Air mixed in oil line
! Metering oil pump malfunction
• Leakage or clogging in oil pipe
• Leakage or clogging in oil nozzle
• Starting system malfunction
• Spark leakage from high-tension leads
• Spark plug malfunction
(w) RX8-Engine Troubleshooting
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