How to solve the unstable idle speed of Fox?

What should I do if Fox's idle speed is unstable?

Solution to unstable idle speed of Fox engine: 1. Adjust, repair or replace the throttle position sensor. 2. Cleaning or replacing the idle speed control valve is basically to set the idle speed with a special decoder. 3. If leakage is found, reseal or replace the phase parts. Although most cars now have fault self-diagnosis systems, there will be cases where the fault self-diagnosis system displays normal codes or codes unrelated to faults. Causes, diagnosis and elimination of unstable idle speed. 1. Idle switch not turned off: fault analysis. When the idle contact is disconnected, the ECU determines that the engine is in a partial load state. Diagnosis: Turn the steering wheel at idle speed. The engine speed does not increase, which can prove this fault. Troubleshooting, adjustment, repair or replacement of throttle position sensor. 2. Idle speed control valve (ISC) failure: failure analysis, due to oil pollution and carbon deposition, the idle speed control valve is slow or blocked, and the throttle valve is closed incorrectly. ECU can't adjust engine idle speed correctly, which leads to unstable idle speed. Diagnosis: Check the execution sound of idle speed control valve. If the sound is not executed, the idle speed control valve will fail. Troubleshooting, cleaning or replacing the idle speed control valve is basically to set the idle speed with a special decoder. 3. Air leakage in the air inlet pipeline: The fault analysis shows that the opening of the idle control valve increases, and the air intake increases accordingly. There is air leakage in the air intake pipeline, and the relationship between the air intake and the opening of the idle control valve will not strictly follow the original function, that is, the air intake suddenly changes with the idle control valve, and the air-air flowmeter cannot measure the real air intake, which leads to the inaccurate control of the air intake by ECU and the unstable idle speed of the engine. Diagnosis: If you hear the inhalation sound of air leakage in the intake pipe, it proves that the air intake system is leaking. Troubleshoot, find leakage, reseal or replace phase components.