🔍 Key Concepts

• Turbocharger function on a four-stroke diesel and how it affects air supply • Relationship between intake manifold pressure, air quantity, and fuel burning • How exhaust temperature changes when an engine runs with less air for the same amount of fuel

💭 Think About

• If the turbocharger stops supplying boost, what happens to the amount of air getting into the cylinders and the manifold pressure? • With less air but the same fuel rack setting, does combustion become hotter or cooler in the cylinders and exhaust? • Which of the options describes the most likely result of reduced air/boost at a given fuel setting?

✅ Before You Answer

• Be clear whether boost failure increases or decreases intake manifold pressure. • Think about whether rich combustion (too much fuel, not enough air) generally raises or lowers exhaust temperature. • Eliminate any choices that conflict with the basic role of a turbocharger: to raise intake air pressure and increase air mass in the cylinders.