What Causes Intermittent Idle Vibration?
1 Answers
The causes of intermittent idle vibration include the following: 1. Engine intake pipe leakage: The intake system contains many intake manifolds or valves. Leakage in these components can allow unwanted gases to enter, leading to excessively high or low concentrations of the air-fuel mixture in the intake manifold. This ultimately results in intermittent engine vibration or weak performance during idle. 2. Fuel system blockage or malfunction: Blockages in the fuel tank vent, fuel tank switch, fuel filter, or fuel lines between the tank and carburetor can prevent the engine from receiving the required fuel supply during idle. This causes the air-fuel mixture to become lean, weakening engine power output and leading to idle vibration. 3. Idle control valve failure: The idle operation of fuel-injected engines is mostly controlled by the idle control valve. The ECU adjusts the opening of the idle control valve based on signals such as engine speed, temperature, and throttle position to maintain stable idle speed. If the valve malfunctions, it can cause uneven air distribution, resulting in fluctuating engine power during idle and vehicle vibration. 4. Engine carbon buildup: Carbon deposits in areas such as the cylinders, throttle, spark plugs, and intake system directly affect engine power output. Excessive carbon buildup reduces ignition energy and intake efficiency, leading to unstable engine power output, idle vibration, and poor acceleration.
