Chevrolet Sail's idle speed fluctuated and suddenly turned off frequently. After cleaning the idle motor, the situation was serious and the steering wheel was dead.

First, check whether there are any symptoms such as carbon deposition or seizure on the accelerator, and if there are, clean it. If not, check the idle switch, throttle position sensor and throttle motor.

Of course, there may be a problem with the crankshaft pulley, because the missing tooth signal in the ECU- crankshaft position sensor signal is the reference point to control the ignition timing, and the missing tooth must maintain a certain positional relationship with the crankshaft.