【Inspection process】
    The standard idling speed of this engine is 750 ± 5Or / min, such as beyond this standard, mainly for the following reasons.
    (1) inlet air leakage. As the D-type EFI system is measured by the intake pipe vacuum to indirectly measure the intake air volume, which through the computer control fuel injection. If there is a leak in the rear of the throttle, the air is sucked from here, the intake air volume increases, the fuel injection quantity increases, the idle speed must rise, so must check whether there is leakage.
    (2) Idle adjustment is not correct. This car has two places where you can change your idling. First, the throttle opening limit screw, this screw is not allowed to adjust, but may also be adjusted, leaving the throttle closed lax. Therefore, it should be checked whether the throttle valve can be completely closed, and when the throttle is fully closed, there should be no clearance between the limit screw and the limit bar. Second, in the engine room on the right (standing in front of the car to see) there is a black variable resistor, the center is an oval protrusion, this device is used to adjust the idle mixing ratio, clockwise rotation thinning, against the needle rotation thicker. But this device can not be adjusted, such as improper adjustment, it will affect the exhaust emissions, so if you have to adjust, should first be connected to the exhaust gas detector and then adjust.
    (3) Idle automatic control device failure. This car is a rotary solenoid valve idling automatic control device, this device according to the engine different conditions and automatically adjust the engine idling speed. Its working principle is the engine water temperature and intake air temperature is in the idle state, whether the use of air conditioning and whether the steering is turned into an electrical signal to the computer, the computer based on these signals to determine a suitable idle speed, and then issued a command to Rotate the solenoid valve to open it to a certain extent, thus achieving the most common idle speed. If the rotary solenoid valve due to the dirt inside the airway is stuck and closed when the lock, or control signal error caused the computer to send an error command, will cause the idle speed is too high.