The diesel engine shown in the illustration can be fitted with a pyrometer at each exhaust elbow. If one of the cylinder pyrometers is reading significantly higher than the others, which of the following should be your FIRST action? Illustration MO-0005

Correct Answer: Option A — Check the pump rack setting.

An abnormally high pyrometer reading indicates excessive thermal energy from a single cylinder, often caused by overfueling due to an incorrect individual fuel pump rack setting. Checking and adjusting the rack is the most direct initial diagnostic step.