No. 8 Engine Runs Rough/Rolling Idle: Notes
WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
DESCRIPTION & POSSIBLE CAUSE
| 8 |
ENGINE RUNS ROUGH/ROLLING IDLE |
| DESCRIPTION |
- Engine speed fluctuates between specified idle speed and lower speed and engine shakes excessively.
- Idle speed is too slow and engine shakes excessively.
|
| POSSIBLE CAUSE |
- Air leakage from intake-air system parts
- A/C system operation is improper
- Erratic signal to ignition coil
- Spark leakage from high-tension leads
- Spark plug malfunction
- Purge solenoid valve malfunction
- Improper operation of electronic throttle control system
- EGR valve malfunction
- Erratic or no signal from CMP sensor
- Low engine compression
- Improper valve timing
- Improper variable valve timing control system operation
- Erratic signal from CKP sensor
- Poor fuel quality
- PCV valve malfunction
- Air cleaner restriction
- Restriction in exhaust system
- Disconnected electrical connectors
- Inadequate fuel pressure
- Fuel pump body mechanical malfunction
- Improper load signal input
- Fuel line restriction or clogging
- Improper fuel injection control operation
- Fuel leakage from fuel injector
- Fuel injector clogging
- Engine overheating
- Vacuum leakage
- Pressure regulator malfunction
WARNING:
The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:
CAUTION:
- Disconnecting/connecting quick release connector without cleaning it may possibly cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.
|