Which of the following describes the effects of a malfunctioning fuel metering system?

A malfunctioning fuel metering system typically disrupts the precise control of fuel delivery to the engine, which can lead to a variety of performance issues. One significant effect is rough idling and decreased power. When the system fails to deliver the correct amount of fuel, the engine may struggle to maintain an even idle, leading to fluctuations or roughness. Additionally, improper fuel metering can result in insufficient fuel reaching the engine during acceleration, causing a noticeable decrease in power output. The overall performance of the vehicle is adversely affected, as the engine requires accurate fuel delivery for optimal combustion and efficiency.

In contrast, a properly functioning fuel metering system would ensure that fuel consumption varies appropriately with driving conditions, thereby contradicting the idea of consistent fuel consumption across varying situations. Similarly, it would not lead to an improved throttle response, as a malfunction would likely hinder the engine's ability to respond quickly to accelerator inputs. Lastly, an optimal engine temperature is dependent on various factors, including fuel mixture and timing, but a faulty fuel system typically does not promote optimal performance or temperature regulation. Thus, the identification of rough idling and decreased power aptly highlights the symptoms of a malfunctioning fuel metering system.