Why Does the Exhaust Pipe of a Natural Gas Engine Spit Fire?
3 Answers
Because some copper wires in the low-voltage wire of the car's distributor are broken, causing insufficient voltage. Specific reasons: When some copper wires in the low-voltage wire of the distributor are broken, the ignition voltage provided to the spark plugs is insufficient, leading to incomplete combustion of gasoline. The unburned fuel-air mixture enters the exhaust pipe and ignites when it encounters sparks in the exhaust gas, causing the exhaust pipe to spit fire. Reasons for backfiring: When the engine temperature is low, although starting is more difficult, the engine can operate normally once started. As the engine temperature rises, the temperature of the ignition coil also increases, and its resistance rises with temperature, resulting in even more insufficient high-voltage electricity generated by the ignition coil. The high-voltage spark becomes weaker or even intermittent. Due to the intermittent sparks, the unburned combustible mixture in the cylinders is expelled into the muffler. When it expands in the muffler and encounters sparks in the exhaust gas, it detonates, manifesting as backfiring from the muffler.
I remember once when I was driving a natural gas vehicle, I suddenly saw flames shooting out of the exhaust pipe, which almost gave me a heart attack. Later, I found out that this was mostly due to unburned fuel igniting inside the pipe, possibly because of an incorrect fuel-air mixture ratio or issues with the ignition system, such as excessive carbon buildup on the spark plugs causing delayed combustion. Prolonged occurrences like this can damage components, and worse, driving with flames is extremely dangerous on the road—it could ignite oil residue under the car or even cause an accident. If you notice this happening, I suggest pulling over immediately, turning off the engine, and checking the issue. Don’t take the risk of continuing to drive—safety comes first above all else. It’s also essential to develop a habit of regularly inspecting the ignition and fuel delivery systems, especially for older cars, which are more prone to such problems, to avoid breakdowns or even more severe consequences.
I usually enjoy researching vehicle systems, and the phenomenon of flames shooting from the exhaust pipes of natural gas engines is quite fascinating. It's typically a post-combustion effect caused by incomplete burning. When the air-fuel ratio is imbalanced or the ignition coil malfunctions, unburned gases suddenly ignite upon encountering oxygen in the hot exhaust pipes. Simply put, it's like blowing on a campfire. I've also noticed this occurs more frequently in cold weather because low temperatures lead to poorer combustion efficiency. It's important to maintain spark plugs and clean carbon deposits. Newer models come with computer control systems that can make timely adjustments to reduce such incidents. Neglecting this issue may lead to engine overheating and damage to more expensive components. Routine maintenance is crucial – don't overlook these minor problems.
