If the opening pressure of a diesel engine fuel injector is greater than specified by the engine manufacturer, what problem might occur?

When the opening pressure of a diesel engine fuel injector exceeds the manufacturer’s specifications, it indicates that the injector is spraying fuel at a higher pressure than intended. This can create several issues, but primarily it tends to affect the quantity of fuel injected into the combustion chamber.

With an elevated opening pressure, the injector may not atomize fuel properly, leading to an incomplete burn during combustion. The atomization of fuel is crucial for creating a fine mist that is necessary for efficient fuel combustion. If the fuel is injected in larger droplets due to high pressure, it may not fully combust, resulting in decreased overall efficiency and power output. Therefore, it is possible for the actual quantity of usable fuel injected to be less effective, which contradicts the expectation that increased pressure would always lead to more fuel being injected.

In contrast, if the opening pressure is lower than specified, you might see more fuel being injected than necessary, resulting in other issues. Consequently, understanding the correct opening pressure is critical for optimal engine performance and fuel efficiency.