Question 149Motor Plants - 1st Asst/Chief

The correct answer is A) the flexibility of high-pressure fuel lines. Injection lag in a diesel engine is caused by the time it takes for the high-pressure fuel to travel from the fuel pump to the injector. If the fuel lines are flexible, this can cause a delay in the fuel reaching the injector, resulting in injection lag. This is because the flexible fuel lines can absorb some of the fuel pressure, slowing down the fuel delivery. The other options are incorrect because they do not directly affect the time it takes for the fuel to reach the injector. A decrease in air temperature or compression pressure, or a change in the cetane number of the fuel, can impact engine performance, but they do not specifically cause injection lag.