Why does a diesel engine stall a few seconds after starting?
2 Answers
The reasons why a diesel engine stalls after starting can be summarized into the following 4 points: 1. Stalling caused by excessive carbon deposits: Carbon deposits usually accumulate in the throttle, spark plugs, cylinders, fuel lines, intake ducts, etc. They are a coking-like substance formed when fuel is exposed to high temperatures. General physical methods are difficult to remove them, and specialized cleaning agents are required for cleaning. 2. Poor fuel quality and clogged fuel injectors: Using low-quality fuel not only produces more carbon deposits but may also clog the fuel injectors, leading to poor atomization. Additionally, low-quality fuel directly affects combustion efficiency, increasing fuel consumption. The carbon monoxide produced from incomplete combustion can accumulate inside the vehicle and may even cause poisoning. 3. Spark plug carbon deposits and insufficient ignition voltage: Carbon deposits on spark plugs can be removed using a combination of physical and chemical methods. Insufficient ignition voltage can be resolved by replacing the spark plugs. 4. Severely depleted battery: If the battery is severely depleted, it can make the engine difficult to start or even prevent it from starting altogether. Generally, a battery has a lifespan of about 4 years.
As a long-time diesel vehicle owner, I've encountered situations where the engine stalls a few seconds after ignition, mainly due to fuel system issues such as a clogged fuel filter or a failing fuel pump, leading to insufficient fuel supply. Diesel engines require continuous fuel pressure to operate; if the filter is too dirty and fuel can't be supplied, the engine stalls. Another common issue is faulty injectors, where dirt or damage causes uneven injection, resulting in startup failure. In cold weather, diesel thickens and becomes harder to ignite, especially if started without sufficient preheating, making it prone to stalling several times. Faulty sensors like the crankshaft position sensor can also send incorrect signals, causing the ECU to shut down the engine. The solution is to first check simple things: replace the filter, ensure clean fuel, and preheat longer. For long-term solutions, consult a professional mechanic and don't delay until the problem severely affects driving.
