What are the reasons for difficult starting of air-cooled diesel engines?
1 Answers
Difficult starting of an air-cooled diesel engine is often due to issues with the fuel injection timing. To address this, readjust the injection timing by removing the flywheel housing and rotating the flywheel to observe the fuel injection pump. When the notch on the cylinder head aligns with the 20-degree mark on the flywheel, the fuel injection pump should just begin to emit fuel. If not, adjust by adding or removing copper shims from the fuel pump. Methods to address difficult starting of air-cooled diesel engines: 1. Preheating during cold seasons: During cold starts, diesel engines often fail to reach the compression ignition temperature of diesel, which is a primary reason for starting difficulties. A practical solution is to add hot water to the engine cooling system for preheating, effectively improving starting performance. 2. Improve cylinder sealing performance: One key difference between diesel and gasoline engines is the compression ignition method, which requires higher cylinder sealing performance. During cold starts, the lack of sufficient oil between piston rings and cylinder walls leads to poor sealing, resulting in repeated failed start attempts. Severe cylinder wear can further degrade sealing performance, making starting even more difficult. 3. Remove air from the fuel system: Loosen the air bleed screw on the high-pressure fuel pump and manually pump fuel to expel air from the high-pressure fuel lines. Then, loosen the fuel pipe connections on each injector, set the throttle to maximum fuel supply position, and crank the engine until fuel flows steadily from each injector's fuel pipe connection.
