What Causes Fluctuating Idle Speed?
1 Answers
Fluctuating idle speed can be attributed to the following reasons: 1. Dirt from the air and sludge from gasoline can easily cause the throttle to become dirty, leading to poor operation of the idle speed motor. 2. Excessive carbon buildup can result in valves not sealing properly, poor fuel injector atomization, and incomplete combustion. 3. A clogged exhaust pipe can cause poor exhaust flow. 4. Air leaks can lead to insufficient vacuum. 5. Aging wiring or issues with the computer board, though this phenomenon is less likely to occur in the short term. Countermeasures: 1. When the engine idle is unstable, the first step is to adjust the idle speed. 2. 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 use compressed air to blow them clear. 3. If the jets are not clogged, stabilize the engine at a certain speed and listen for air leaks at the intake manifold or the lower gasket of the carburetor. If leaks are found, tighten the screws or adjust the gasket thickness to resolve the issue. 4. If the idle is unstable and accompanied by a decrease in engine power, further inspect the spark plugs, valve sealing performance, and ignition timing. If necessary, perform maintenance or adjustments.
