Model: a 02 Toyota Land Cruiser 4700, 1FZ-FE engine, mileage 95,000 km.
    Symptom: the owner of the car since the accident since the repair, there is the phenomenon of idling regular jitter, before any failure. Take this car after the test, the engine idling operation, sitting in the cab when the steering wheel obviously feel the engine regular jitter. When the engine speed is higher than the idle speed, jitter failure disappears, regardless of any speed when running without adverse effects.
    Trouble checking and troubleshooting: let the engine idle operation, with X-431 detector to read the engine control system and data flow, are within the normal range, and no fault code display. Since the engine control system is normal, should focus on checking the high voltage. Owners prompted the car's engine had overhaul once, in other repair plants have also been tested, this also replaced the high-voltage lines, spark plugs and ignition coil. After the change phenomenon is more serious than before, the engine part of the mechanical re-decomposition after the installation, the fault remains the same. In the inspection found that high-voltage lines for non-original parts, replace the original high-voltage lines, the failure phenomenon than before, but not completely ruled out. Remove the spark plug to observe, using a platinum spark plug, working properly. Check the original factory maintenance manual that the car's spark plug for the general type of spark plug, all replaced by Toyota dedicated ordinary spark plug, the test, the fault disappeared.