Unstable RPM and wandering of diesel generator

1. Unstable idle: Refers to the phenomenon where the diesel generator fluctuates between fast and slow speeds while idling, with irregularity and vibration. It is also prone to stalling during rapid deceleration, gear shifting, or under load. This issue is often caused by a malfunctioning governor.

Analysis of the reasons for the diesel generator rental: mainly due to the following factors.

(1) Flyball Wear

(2) Idle speed spring elasticity has deteriorated or is incorrectly adjusted

(3) Incorrect Speed Spring Adjustment

(4) Low-pressure oil supply is not smooth or contains water and air

(5) Excessive wear on the conical bearing of the camshaft supporting the fuel pump cam

2. "Surging": What is referred to as "surging" is a phenomenon where diesel generators exhibit a cyclically fluctuating speed, alternating between faster and slower rates over a longer period, within the low to medium speed range. This is a result of the speed control response lagging excessively behind the actual speed changes.

The reasons are mainly as follows.

(1) Internal lever of the speed regulator is loose due to wear on the connecting pin holes

(2) The oil-feeding ratchet is not sufficiently flexible

(3) Incorrect Speed Control Spring Adjustment - Similar to the case of unstable idle when the speed control spring is adjusted improperly, this situation manifests as "drifting" because the speed control spring and the fuel supply rack cannot work together flexibly.