A diesel engine of screw air compressor machine or generator that starts but fails to keep running-commonly known as "starting successfully but quickly stalling"-is a frequent fault. To address this issue, the following aspects should be checked and resolved.
1. Check if the idle setting is too low
Low idle speed is a common cause of diesel engine stalling after startup. If the idle speed setting is below the minimum speed required for stable operation, the engine may fail to maintain steady running after starting. In such cases, check the controller's idle parameters and appropriately increase the idle setting to ensure smooth and continuous operation of the unit.
2. Avoid starting under load
Some operators fail to remove the load before starting the diesel engine, causing the unit to start under load. This significantly increases the starting resistance, leading to rapid stalling of the engine due to excessive load after startup. The correct procedure is to ensure the unit starts under no load, and only gradually apply the load once the engine has stabilized.
3. Investigate fuel quality issues
Poor-quality fuel is a significant factor causing unstable operation in diesel engines. Substandard fuel may contain impurities, moisture, or incorrect specifications, leading to incomplete combustion, poor fuel delivery, or even engine stalling. If fuel quality is suspected, drain all remaining fuel from the tank and thoroughly clean the entire fuel system-including the fuel tank, fuel lines, and filters-before refilling with high-quality, standard-compliant fuel.
4. Bleed air from the fuel system
Air entering the fuel system can disrupt normal fuel delivery continuity, causing the diesel engine to stall after starting due to interrupted fuel supply. In such cases, it is necessary to bleed air from the fuel system. This is typically done by loosening the bleeder screw on the fuel injection pump or filter, manually pumping fuel until clean fuel without bubbles is discharged, then tightening the bleeder screw again.
In summary, when a diesel engine fails to run continuously after starting, the fault can be systematically diagnosed in the following order: first check idle performance, then operating conditions, followed by fuel quality, and finally eliminate air-related issues. Proper operation and regular maintenance can effectively reduce the occurrence of such faults.
Recommended Stable Diesel Generator and Diesel Screw Air Compressor
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