What are the symptoms of a damaged diesel pump plunger?

[DelJonathan]

Diesel pump plunger damage symptoms include: 1. False overspeeding refers to the diesel engine starting with normal idle speed, but failing to decelerate after releasing the throttle at high speed. This occurs when the injector plunger is worn, and the fuel rack is set to idle fuel quantity at the idle position. 2. No fuel flows from the high-pressure fuel line, but there is fuel in the low-pressure circuit, and the diesel engine fails to start, indicating the fuel supply rack is stuck in the no-fuel position. In this case, timely repair of the fuel injection pump is also required. 3. Fluctuating engine speed is a sign of inflexible fuel supply rack movement or excessive wear of internal governor components, leading to increased clearance. Therefore, the fuel injection pump also needs repair.