Which of the following would indicate a potential problem with fuel injector performance over time?

Variations in engine power output signal potential problems with fuel injector performance because consistent fuel delivery is crucial for maintaining stable engine performance. If the fuel injectors are malfunctioning, they may fail to deliver the correct amount of fuel to the engine at all times, leading to fluctuations in power output during operation. This irregularity can stem from several issues, such as clogging, improper spray patterns, or electrical problems affecting the injector's operation.

When fuel injectors are functioning optimally, the engine should experience smooth and consistent power output. If there are variations, it suggests that the injector may not be supplying a uniform amount of fuel, which directly impacts the combustion process and, consequently, the power produced by the engine. Monitoring this aspect is vital for diagnosing injector issues before they lead to more significant engine problems.

In contrast, signs like a smooth engine start, decreased fuel consumption, or consistent exhaust color do not directly indicate injector issues. A smooth start typically implies that the initial ignition and fuel delivery are functioning well. Decreased fuel consumption could suggest more efficient engine operation, while consistent exhaust color often indicates that the combustion process is stable and balanced, ruling out issues related to excess fuel delivery.