What Causes a Sudden Increase in Idle Speed While Driving?

[StCharlie]

The reasons for a sudden increase in idle speed while driving are: 1. The idle switch does not close; 2. The idle control valve is faulty; 3. There is an air leak in the intake pipe; 4. Incorrect valve timing; 5. The fuel injector is dripping or clogged; 6. The exhaust system is blocked; 7. The EGR valve opens during idle conditions. The solutions for a sudden increase in idle speed while driving are: 1. Adjust or replace the throttle position sensor; 2. Clean or replace the idle control valve and perform a basic idle setting with a decoder; 3. Locate the leak, reseal or replace the relevant components; 4. Check the timing marks and readjust the valve timing according to standards; 5. Clean and inspect each fuel injector's spray volume and check for blockages or leaks; 6. Replace the three-way catalytic converter; 7. Remove carbon buildup from the EGR valve or replace the EGR valve.