What consequence can result from excessive fuel injection into a diesel engine?

Excessive fuel injection into a diesel engine can lead to engine knocking, which is a form of abnormal combustion. In a diesel engine, the fuel is injected into the combustion chamber under high pressure and ignited by the heat of compression. When too much fuel is introduced, it can create a scenario where the air-fuel mixture becomes too rich. This may lead to uneven combustion, where the added fuel doesn't have enough time to burn completely before the next cycle begins, resulting in a knocking or pinging sound.

Engine knocking can cause prolonged stress on the engine components, leading to increased wear and potential damage over time. It also impacts overall engine efficiency and performance, highlighting the importance of maintaining proper fuel injection rates to ensure optimal combustion conditions and avoid this detrimental outcome.