Fault detection: the test found only 30-50km / h speed, and in the running of the phenomenon of Suddenly slow, we call it to speed up the phenomenon. The owner told the car before the failure of this phenomenon, and now simply can not drive. You car phenomenon often occurs in the idle conditions, rarely encountered acceleration also has a car fault. In order to more accurately analyze this phenomenon, we will lift the car lift to do the accelerated test, when slowly depress the accelerator pedal, the engine speed increases, when the speed rose to nearly 2000r / min no longer raise , Continue to step on the accelerator pedal invalid, but the phenomenon of speed decline. Slam the throttle carefully observed, when the speed down to 1500r / min when the speed began to rise, until nearly 2000r / min and then repeated the phenomenon of decline, simply not by the throttle control, release the throttle into the idle conditions, the speed is very Stable (800r / min).
    According to past experience, this will not be off the oil function in the opening? This idea prompted us to confirm. So we removed an injector plug access test lamp, and repeat the above accelerated test, it turned out that when the engine speed rose to 2000r / min, the test light goes out, speed down to 1500r / min when the test light and bright From the engine speed is also with the lights off the light and rhythm of the fluctuations, thus confirming the opening of the oil function, the computer off the oil function has three conditions: ① high speed off the oil; ② high speed off the oil; ③ slow off oil The Analysis that the car should be a series of slow oil. Although this time to accelerate rather than slow down, but the computer to determine the conditions as long as the idle conditions, speed exceeds the limit speed will enable the oil off function.
    After the test and analysis, the problem must be in the idle switch, it is likely that the idle switch in the acceleration is also closed state. As the car for the direct-acting idling control, the idle switch is not in the throttle position sensor, but in the idle speed of the implementation of the extension of the motor at the top of the top of the idler has been top in the throttle board, the idle switch is always closed , When the accelerator throttle in the throttle line driven by the opening of a large throttle flap, then the top of the idling motor telescopic rod from the throttle board, so the idle switch to open the state. In order to confirm the status of the idle switch, access to the data and measured the idle motor position sensor connector on the 3rd foot (idle switch signal), and sure the same results, regardless of the idle conditions or accelerated conditions, the switch is always closed, The inspection found that the idle motor telescopic rod distortion distortion, contact switch can not open, after a simple treatment, the switch function recovery, and then test, the fault disappears.
    Summary: This car's accelerated car, from the surface it does not meet the slowdown in oil off the logic, but it is in line with the conditions of slow oil. This car because the idle switch normally closed computer is always sentenced to idle conditions, when accelerating more than 2000r / min, the computer will think that the speed exceeds the idle limit, so the computer uses the oil off function to increase the speed of control - oil control. Due to oil and restore the oil supply function, so the engine power has a significant change, which led to accelerate the car.
    Fault Summary: the engine idling car phenomenon is more common, but in the accelerated conditions are not easy to happen. Accelerated car phenomenon is a slow speed of the law suddenly slow and slow running state, it accelerates the jitter, speed up the car, to accelerate the movement and other phenomena are fundamentally different:
    1, accelerated jitter - is a fast irregular fluctuations, it is mixed with too thin, weak fire, lack of cylinder or some mechanical reasons.
    2, to speed up the car - is a kind of acceleration when the brake failure occurred suddenly, dynamic changes were blunt, mostly for the control or ignition of the reasons, such as a device, a plug, a line of bad contact caused by fire Off the oil or control the moment of poor work and lead to instant no power.
    3, to speed up the movement - is a sudden power of the sudden increase in the dynamic sense of impulse, it is more complex reasons, such as the main sensor, system oil pressure, ignition system and other work good times and bad, especially in the control A link bad and so on.
    Accelerated car phenomenon is accelerated although the conditions, but it is associated with idle control and a link, mostly for the reasons for slow down oil control.