Question 463Motor Plants - Assistant Engineer

The correct answer is A) the air intake is restricted. A diesel engine requires a steady supply of clean air to the engine's intake in order to function properly. If the air intake is restricted, it can be difficult for the engine to draw in enough air to support combustion, making the engine hard to start. This is due to the nature of how diesel engines operate, which rely on compression ignition rather than spark ignition. The other options are incorrect because: B) cranking the engine too fast would not directly cause a hard start, C) a faulty vibration dampener would not impact the engine's ability to start, and D) low exhaust back pressure would not prevent the engine from starting, as it does not directly affect the air intake.