What is the reason for the unstable idle speed of modern Santa Fe 2.7?

1, idle switch is not turned off. Diagnostic method: turn on the air conditioner and turn the steering wheel at idle speed. The engine speed does not increase, which can prove this fault. Troubleshooting: Adjust, repair or replace the throttle position sensor. 2. Idle speed control valve (ISC) fault diagnosis method: Check the action sound of the idle speed control valve. If there is no action sound, the idle speed control valve is faulty. Troubleshooting: Clean or replace the idle speed control valve, and set the idle speed with a special decoder. 3. Diagnosis method of air leakage in the air intake pipe: If you hear the sniffing sound of air leakage in the air intake pipe, it proves that the air intake system is leaking. Troubleshooting: Find the leakage, reseal or replace the phase parts.

4. The fuel injector leaks or is blocked.

Diagnostic method: Use a stethoscope to check whether the fuel injector makes clicking sound or measure the fuel injection quantity of the fuel injector. If the injector does not click or the injection quantity exceeds the standard, the injector is faulty.

Troubleshooting: Clean the injectors and check the fuel injection quantity of each injector to ensure that there is no blockage or leakage.