What is the high idle speed of Corolla cold car 1500?

The reasons for the high idle speed of Corolla in Pacific Auto Network are usually air leakage in vacuum tube, faulty throttle position sensor, dirty throttle, stuck throttle motor, air conditioning pressure switch not turned off, water temperature sensor damaged or open circuit.

Possible reasons for excessive idle speed are:

1, whether there is a problem with the signal of water temperature sensor, this computer is used to see whether the signal of water temperature is complementary to the engine;

2. Check whether there is air leakage;

3. Considering the reason of the throttle body, the opening of the throttle body can be looked at by computer. If the card is stuck, the throttle body can be cleaned. Then cut off the battery cable and wait 60 seconds to resume initialization.

After the vehicle is started, the engine speed will be very high, which is the high idle speed of the cold car. This is computer-controlled, mainly because the ambient temperature is low and the engine is not easy to burn when it is ignited. At the same time, in order to warm up the engine quickly, the computer control speed is relatively high, and the general speed can reach nearly 2000 rpm. As the temperature rises, this speed will gradually drop to the standard idle speed. If there is such a high speed after the hot car, it must be abnormal.

Improve the stability of engine operation. If the engine speed is too low and the load is too high, it will affect the stability of the engine, leading to the high and low speed, and the vehicle will have a slight sense of frustration and discomfort.

This situation is often encountered in vehicle development. When the engine is working normally, if the load is too high, but the engine output torque is too low, in this case, the high load will reduce the engine speed and there will be a danger of flameout.

At this time, the engine ECU will detect this fault, and will deliberately increase the engine fuel injection and engine output torque, so that the engine speed will increase accordingly; When the engine speed rises to a certain range, the fuel injection of the engine will decrease, but the resistance of the engine is still relatively large, which leads to the decrease of the engine speed, thus making the engine speed higher and lower for a while.