No. 8 Engine Runs Rough/Rolling Idle: Notes
NO. 8 ENGINE RUNS ROUGH/ROLLING IDLE DESCRIPTION AND POSSIBLE CAUSE
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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 |
- Idle learning of drive-by-wire control system is not completed.
- Electrical connector disconnected
- External fuel shut off or accessory
- Poor fuel quality
- Fuse malfunction
- Ignition wiring malfunction
- Air leakage from intake air system
- Vacuum leakage
- PCM ground circuit (1E, 1F, 1G or 1BE) malfunction
- Improper installation EGR valve
- Improper operation of drive-by-wire control system
- PCM DTC is stored.
- Engine overheating
- MAF sensor or related wiring harness malfunction
- Improper operation of A/C system
- CKP sensor and teeth of crankshaft pulley malfunction
- Ignition coil or related wiring harness malfunction
- Spark plug malfunction
- Excessive or insufficient fuel pressure
- Fuel pump relay or fuel pump circuit malfunction
- Restriction in fuel line
- Pressure regulator malfunction (built-into fuel pump unit)
- Fuel pump unit malfunction
- Fuel leakage from fuel system
- Fuel injector malfunction
- Purge solenoid valve malfunction
- EVAP control system malfunction
- Exhaust system part malfunction
- CMP sensor and teeth of camshaft malfunction
- EGR valve malfunction
- Improper operation of variable valve timing control system
- Low engine compression
- PCV valve malfunction
- Improper valve timing
WARNING:
- The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:
- Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
- Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this service information. (See BEFORE SERVICE PRECAUTION
.) (See AFTER SERVICE PRECAUTION
.)
CAUTION:
- Disconnecting/connecting the quick release connector without cleaning it may cause damage to the fuel pipe and the quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.
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