What Causes the Throttle of a Single-Cylinder Diesel Engine to Fluctuate?
2 Answers
It is mainly related to the fuel injection volume from the injector, the atomization effect of the fuel, and the mixing ratio with air. A common issue is severe contamination of the injector, which can clog it and lead to poor or uneven fuel injection. This results in inconsistent fuel delivery, causing the throttle to fluctuate. Additional Information: 1. Composition of a Diesel Engine: The internal system of a diesel engine consists of power transmission components, the engine block and main bearings, valves, the fuel system and governor, lubrication system, cooling system, and the starting system of the internal combustion engine. 2. Diesel Engine Fuel: The primary fuel for diesel engines is diesel. Typically, high-speed diesel engines use light diesel, while medium- and low-speed diesel engines may use either light or heavy diesel. Diesel engines employ an injection pump and injector to spray fuel into the cylinder under high pressure. The injected fuel atomizes and mixes with air for combustion. As a result, diesel engines can use heavier or lower-quality fuels with poor volatility, such as crude oil and residual oil.
Fluctuating throttle may be related to the fuel system. I just repaired a single-cylinder diesel engine, where the most common issue was fuel line blockage—such as a dirty diesel filter or impurities in the fuel restricting flow and causing unstable throttle. Additionally, worn injector nozzles or uneven injection pressure can cause this, especially if the spray holes get clogged after long-term use. The governor also needs checking; in single-cylinder diesel engines, it stabilizes the speed, and if components are loose or worn, it can cause erratic behavior. The air system shouldn’t be overlooked either—a dirty air filter affects air intake, leading to incomplete combustion. If operating in harsh environments like construction sites or farms, dust buildup worsens the problem. I recommend starting by cleaning the filters and inspecting fuel lines, then checking the governor if needed. This won’t cost much and prevents further damage. Don’t wait until the machine stalls to realize it’s a major issue, as it impacts work efficiency.
