Comprehensive Analysis and Solutions for Cummins Generator Instability
Currently popular diesel generator sets on the market include Cummins generators, Volvo diesel generator sets, and others. During prolonged use, users may encounter situations where the Cummins diesel generator set experiences fluctuating RPM after startup. This is typically caused by malfunctioning fuel adjustment systems. What exactly is happening? Below, Lide provides an analysis and some solutions:
Cause Analysis:
1. Poor cylinder performance in the Cummins generator causes uneven compression pressure across cylinders.
2. Air, moisture, or restricted fuel flow within the fuel supply system.
3. Significant variation in fuel delivery from individual plungers within the high-pressure fuel pump.
4. Weakened tension in the governor's speed control spring, altering its regulation function.
5. The governor fails to reach minimum speed.
Solutions:
1. Inspect the oil dipstick in the engine oil pan to determine if low oil viscosity or excessive oil volume causes oil to enter the combustion chamber, where it evaporates into unburned oil vapor expelled through the exhaust pipe. However, inspection confirms the oil quality and quantity comply with engine specifications.
2. Loosen the high-pressure fuel pump bleed screw and press the hand pump to purge air from the fuel system.
3. Tighten the return screws on the engine's high- and low-pressure fuel lines.
4. After starting the engine, increase speed to approximately 1000 rpm. Observe if the speed stabilizes. If the engine's running noise remains unstable, the fault persists.