Why does the engine idle shake after converting to gas?

[McCharles]

The reasons for engine idle shake after converting to gas are as follows: Severe engine carbon buildup: Engine carbon buildup is the main cause of car shaking. When there is excessive carbon buildup inside the engine, the gasoline sprayed by the fuel injector during cold starts will be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts, which can easily cause shaking. Ignition system malfunction: Excessive carbon buildup on the spark plugs or excessively large ignition gaps can lead to ignition failure. Fuel pressure issues: Abnormal fuel pump supply pressure or incorrect readings from the intake pressure sensor can easily cause poor fuel pump performance, leading to vehicle shaking.

[LeahAnn]

Speaking of engine idle vibration after CNG conversion, I've had firsthand experience—it felt like driving a massage chair with all the shaking. The issue lies in the improperly adjusted gas-to-air mixture ratio. Natural gas burns differently from gasoline, and without precise coordination, uneven combustion at idle causes vibrations. Additionally, pay attention to the ignition system: worn spark plugs or aging high-voltage lines produce weaker sparks at low RPMs, exacerbating the problem. Post-conversion, the control system needs to adapt to the new fuel, but if self-adaptation fails, the ECU (the engine's brain) can't optimize parameters, leading to unstable idle. I recommend promptly checking the gas regulator and oxygen sensor to prevent carbon buildup from affecting performance. It's best to return to the conversion shop for professional fine-tuning—don’t wait until it worsens, as this can avoid shortening the engine's overall lifespan.

[DeZane]

After converting to gas, the idle was shaky. When driving on city roads, it felt like tiptoeing. Later, it was found that the gas system wasn't installed tightly enough, with slight leaks causing an imbalance in the air-fuel mixture, leading to uneven combustion at idle and resulting in shaking. If ignition components like spark plugs and wires are old, they struggle to provide a stable spark at low RPMs, making the shaking more likely. Another key point is that the control unit needs time to learn the characteristics of the new fuel. If it fails to adapt, the idle becomes unstable. It's recommended to first check if the plugs and wiring connections are secure before rushing to spend big on replacement parts. Getting a professional conversion shop to recalibrate the parameters is a more cost-effective and reliable solution, avoiding high subsequent repair costs and ensuring smooth operation without issues.

[StOlive]

Idle shaking is common after converting to natural gas. I was quite nervous when I encountered it, as this instability affects driving safety. The root cause may be an imbalance in the air-fuel mixture ratio, where the natural gas is not evenly mixed with air; or ignition issues such as worn spark plugs leading to incomplete combustion. Severe shaking at idle may even cause stalling, increasing the risk of accidents, so it should not be taken lightly. Quickly visit the conversion shop for an inspection and system calibration to ensure stability. Don't skip maintenance to save money—regular cleaning of related components can extend engine life and ensure safety.