🔍 Key Concepts

• relationship between firing pressure, exhaust temperature, and fuel quantity/timing in a diesel cylinder • how early vs. late fuel injection timing affects peak cylinder pressure and exhaust temperature • what changing scavenge air pressure or fuel pump/booster pressure typically does to combustion

💭 Think About

• If one cylinder has both high firing pressure and high exhaust temperature, what does that tell you about the amount and timing of fuel being burned in that cylinder compared to the others? • Which adjustment would you use to slightly reduce the rate of pressure rise and peak temperature in that cylinder without starving it of air? • Think about which options would tend to make combustion hotter or cooler, and which mainly affect delivery volume versus timing.

✅ Before You Answer

• Identify which option directly changes injection timing versus which change fuel quantity or air supply • Consider whether increasing scavenge air pressure would usually raise or lower peak firing pressure and exhaust temperature • Verify which control you would normally use to correct an overloaded or over-fueled single cylinder without degrading overall engine performance