Mazda RX-8 Manual page 137

NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE
12 LACK/LOSS OF POWER  ACCELERATION/CRUISE
The performance is poor under a load (e.g., power loss when climbing hills).
DESCRIPTION
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POSSIBLE
CAUSE
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Vacuum leakage
Air leakage from intake-air
system
Air cleaner restriction
Air suction at intake-air system
(between MAF sensor and intake
ports)
Throttle body malfunction
Improper SSV operation
Improper APV operation*
Improper VDI operation
Improper operation of drive-by-
wire control system (abnormal
accelerator position and TP
signals to PCM)
Drive-by-wire control system
operates in fail-safe mode
(abnormal accelerator position
and TP signal to PCM)
Poor fuel quality
Inadequate fuel pressure
Pressure regulator (integrated in
fuel pump unit)
Fuel pump mechanical
malfunction
Fuel line restriction or clogging
Fuel injector improper operation
Fuel injector malfunction
(leakage, clogging, improper
injection amount)
Intermittent open or short in fuel
pump related circuit
Restriction in exhaust system
Leakage or damaged exhaust
manifold
Purge solenoid valve malfunction
(stuck open)
Erratic signal from eccentric shaft
position sensor
Improper ignition timing control
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(abnormal ECT, IAT, MAF and knock
sensor signals to PCM)
Improper fuel injection control (abnormal
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MAF, ECT, front/rear HO2S and knock
sensor signals to PCM)
MAF sensor improper installation
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Spark leakage from high-tension leads
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Spark plug malfunction
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Incorrect spark plug heat range
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Engine overheating
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Low engine compression
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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
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pipe
Leakage or clogging in oil
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nozzle
Metering oil pump malfunction
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Improper metering oil pump control
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operation
Improper A/C system operation
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Brake dragging
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Low tire pressure
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AT malfunction (AT)
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Improper operation of torque converter
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clutch control (AT)
Clutch malfunction (MT)
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(w) RX8-Engine Troubleshooting
Page 88