Question 152Motor Plants - 1st Asst/Chief

The correct answer is C) low compression temperature. Poor combustion in a diesel engine can be caused by low compression temperature. In a diesel engine, the air is compressed to a high pressure and temperature, which then ignites the fuel injected into the cylinder. If the compression temperature is too low, the fuel may not ignite properly, leading to incomplete combustion and poor engine performance. The other options are incorrect because: A) High scavenge air pressure would improve combustion by providing more oxygen. B) Low exhaust pressure would not directly cause poor combustion. D) High compression pressure would actually enhance combustion by increasing the temperature.