Automotive engine idle speed is lower than or exceed the specified range, there will be phase flame, speed instability and so on.
    1, how to do unstable idle ?

    Unstable idle speed as follows: idle, the engine shaking speed uneven. The causes are: the amount of idle air plug the hole, working poor idling devices, individual cylinder spark spark plug is too weak, individual Mifengbuyan valve, intake manifold leak, ignition too early or too late, idling adjustment inappropriate. Unstable engine idling, the first idle speed should be adjusted, such as the idle speed adjustment can not eliminate failure, you should check the idle speed and idle air volume orifice hole is blocked, such as orifice clogging, gasoline or acetone can be cleaned and blown through with compressed air; such as the orifice is not clogged, the engine speed should be stabilized at a certain speed, the police listen to the intake manifold or carburetor, the bottom liner for leaks, where there is leakage, and can be screws or Canada, reduction method to eliminate gasket. Accompanied by instability, such as engine idling down the phenomenon of power, the work should further examine the spark plugs, valve sealing performance and ignition timing is correct, when necessary, for maintenance, adjustment.

    2, how to distinguish bad idle?

    The engine working properly, should be able to 300-500r/min uniform operating speed range. If the engine speed exceeds the minimum stable speed range, or in this speed range there turn off the engine, speed instability, that is no idle or idling bad. Bad when idling, according to its failure characteristics will be divided into idle shutdown, idle instability and excessive idling. If the engine starts, from low speed to high speed running is good, but release the accelerator pedal immediately after a shutdown, or instability in the first operation and then stalled, for the idle shutdown failure. If the engine idle is not smooth, the exhaust pipe was given a "sudden, sudden" sound, then the idle speed is generally unstable failure. If the engine speed is above the minimum range of stability, can not make this speed is reduced and because, for the idle speed is too high or no idle problems.

    3, how to adjust idle speed?

    Adjust the idle speed work must be in the engine temperature is normal, proper valve clearance, the ignition system normal circumstances, the pipe sealed, full choke, the throttle can be closed tightly so under normal conditions. Adjustment, first unscrew the throttle adjustment screw, so that the minimum stable engine speed. Then screw with a screwdriver to adjust idle speed screw, when the engine is about to turn off, and then slowly unscrew the idle speed adjustment screw, so that the engine steady operation and achieve high speed. Throttle opening and then rotating the adjustment screw, so that the engine speed as a minimum. Then adjust the idle speed adjustment screw, so that engine speed increased. This is repeated until the minimum throttle opening (close off), the engine is operating at the lowest steady speed. Finally, improving the speed and the sudden closure of the throttle, turn the engine does not stall still appropriate.

    4, how do turn off idle?

    Turn off the engine idling, the first based on the actual situation on the idle speed adjustment (if specific reasons for failure, may also be maintenance.) Adjustment, such as the fault disappears, is the idle screw adjusted. Adjustment, such as the fault can not disappear, you can throttle a little bigger, to keep the engine running, so check with cotton or paper carburetor, intake manifold gasket for leaks, if not leak, removable check under the idling orifice, and also blowing through idle oil path, and then refitted test, then if the fault disappears, indicating idle idle oil duct orifice and clogging. For the carburetor with idle valve, idle speed should also check the solenoid valve circuit is normal, if it is not normal because of electromagnetic coil circuit caused by the amount of idle fuel hole closed, then the idle cut-off valve should be repaired.

    5,  how to do deal with the high idle speed?

    Engine idle too high, you should first start the engine, and then hand control of the throttle arm, so that the throttle closed. So when the normal idle speed, throttle extension spring was too soft, replace the extension spring. Close the throttle hand control as ineffective, it should check whether the throttle shaft or throttle off Songkuang is tight, such as throttle or throttle shaft Songkuang lax off, it should be trimmed; such as throttle properly, you should check whether there is a minor leak under the throttle and, if air leaks should be eliminated, if no response to further adjust the idle until the idle speed right up.