What causes slight fluctuations in the idle speed needle?
1 Answers
Reasons for slight fluctuations in the idle speed needle: 1. Poor performance of spark plugs; 2. Vacuum tube leakage; 3. High-voltage wire leakage; 4. PCV valve blockage; 5. Faulty throttle position sensor; 6. Malfunction of the idle stepper motor; 7. Failure of the idle control valve; 8. Abnormal throttle opening; 9. Air intake system leakage. Solution: First, adjust the idle speed. If the issue persists after adjustment, check whether the idle jet and idle air jet are clogged. If they are clogged, clean them with gasoline or acetone and blow them through with compressed air. If the jets are not clogged, stabilize the engine speed at a certain level and listen for any air leakage at the intake manifold or the middle and lower gaskets of the carburetor. If leakage is detected, it can be resolved by tightening screws or adjusting the gaskets.