What causes unstable idle speed in natural gas vehicles?

[VanAriel]

The reasons for unstable idle speed in natural gas vehicles are as follows: 1. Dirty valves: The valves need to be cleaned. 2. Spark plug quality issues: The spark plugs need to be replaced. 3. Issues with the gas conversion kit: Possible problems with the electronic control system, pressure reducer, or fuel rail quality. 4. Conversion technical issues: The fuel rail nozzle may be too large or too small, or the electronic control system and pressure reducer may not precisely control the injection timing and quantity. Information about car idle speed is as follows: 1. Idle speed: Refers to the engine running without load, only overcoming the internal friction resistance of its own components, without outputting power externally. The minimum speed required to maintain stable engine operation is called idle speed, which is one of the five basic operating conditions of an engine. 2. Adjustment: Idle speed can be adjusted by changing the throttle opening size, idle fuel supply quantity, etc.

[AutumnFitz]

My car has also experienced unstable idling before, like when waiting at a red light, the car would tremble and the tachometer needle would jump up and down. The most common causes are excessive carbon buildup in the throttle body blocking the intake, or issues with the ignition system. Worn-out spark plugs can lead to insufficient ignition energy, making the car shake like a sieve. A faulty oxygen sensor can also cause the ECU to miscalculate fuel injection. Oh, and vacuum leaks can create this problem too, especially those rubber hoses that crack after seven or eight years of use. If cleaning the throttle body and replacing spark plugs don't fix it, you'll need to check the idle control valve or engine mounts. These all require inspection by a reliable mechanic - prolonged unstable idling not only wastes fuel but may also damage the engine.

[LeMichael]

Last time I encountered severe engine idling vibration, I initially thought it was a fuel quality issue. Later I discovered there are actually multiple causes - dirty throttle body being the most common (a simple cleaning costs around 100 yuan). Other culprits like aging ignition coils or clogged fuel injectors can also make the car gasp during idle. Another scenario is when the fuel filter hasn't been replaced for too long, causing unstable fuel delivery and vibrations. Now I proactively replace the filter every 20,000 km and change spark plugs according to the maintenance manual. With these preventive measures in place, idle instability issues rarely occur. Car maintenance should be like taking care of your health - preventive measures are far more cost-effective than post-failure repairs.

[VanAmy]

Unstable idle speed can actually have several possible causes. Poor fuel quality can lead to incomplete combustion, which will definitely make the car shake. If the air filter hasn't been replaced for too long, it can also affect the air intake volume. Additionally, if the engine mount bushings are worn out, the idle vibration will be particularly noticeable. I've been fooled by this before - had to replace the entire set of mounts to fix it. Now I've learned my lesson: regular fuel system cleaning and using fuel from reputable gas stations, and these minor issues basically don't occur anymore.

[Pierce]

There are quite a variety of reasons for unstable idling. A faulty throttle position sensor is quite common - when it malfunctions, the ECU can't properly control the air intake. Clogged fuel injectors causing poor fuel delivery is another contributing factor. The most annoying case I've encountered was poor contact in the engine wiring harness - the mechanic spent half a day diagnosing before finding it was just a loose connector. Pay extra attention during routine maintenance; checking all connectors every 5,000 km can help detect many potential issues early.

[JuniperLynn]

Don't panic when encountering unstable idling, most cases can be initially checked by yourself. Open the engine hood, start the car and listen for any hissing sound, which indicates vacuum hose leakage. Remove a spark plug to check if the electrode is eroded. A malfunctioning fuel pump can also cause fuel supply interruption, at which point the tachometer will suddenly drop. Recently, it's been found that fault codes from electronic throttle pedals can also trigger this issue, though it's relatively rare. Regular carbon cleaning and filter replacement are crucial preventive measures that can effectively avoid such problems.