🔍 Key Concepts

• diesel engine starting requirements (air temperature, compression, fuel quality) • relationship between air temperature, compression, and fuel ignition in a diesel engine • effects of fuel dilution in lube oil vs direct effects on starting

💭 Think About

• Which conditions help the air–fuel mixture reach ignition temperature in a diesel, and which conditions make this harder? • Among the options, which ones are generally beneficial for starting, and which ones would tend to prevent the fuel from igniting properly? • Does dilution of lube oil with fuel directly stop the engine from firing, or is its main impact on long‑term wear and lubrication?

✅ Before You Answer

• Identify which options improve combustion conditions (good for starting) and which worsen them (bad for starting). • Consider how air charge temperature affects the ability of compressed air to ignite fuel without a spark. • Separate problems that cause immediate failure to start from those that mainly cause maintenance or long‑term damage.