What is the high idle speed of Nissan Bluebird engine?

There are several reasons for the high idle speed of Nissan Bluebird engine: 1, and the idle switch is not turned off. 2. Idle speed control valve is faulty. 3. Air inlet pipe leaks. 4. Wrong valve timing. 5. The fuel injector leaks or is blocked. 6. The exhaust system is blocked. 7.EGR valve opens at idle speed. Solution: 1 Adjust or replace the throttle position sensor. 2. Clean or replace the idle speed control valve, and basically set the idle speed with a special decoder. 3. Find the leakage, reseal or replace the relevant parts. 4. Check the timing mark and readjust the valve timing according to the standard. 5. Clean and check the fuel injection quantity of each injector to make sure there is no blockage or leakage. 6. Replace the three-way catalytic converter. 7. Remove the carbon deposit on the EGR valve or replace the EGR valve.