Jianghuai Heyue RS 1.8, ran 26,000, the fault light was on, and the neutral idle speed was more than 2,000 revolutions. I don't know why.

First of all, the fault light is on, which proves that the engine electronic control system is faulty and the fault code is memorized. Secondly, the normal idle speed is about 800 rpm, and your car only runs more than 20,000, so the conclusion is two: 1, the idle solenoid valve is damaged, and the idle speed cannot be adjusted, so the idle speed is high. 2. The intake pressure sensor is faulty, or the intake pipe behind the throttle is leaking. You can read the fault code with the decoder first, and then determine the maintenance.