A diesel engine is operating under a normal...

A diesel engine is operating under a normal...

Question 1 of 270705eccefa2bacbc34ba4d47b3f

A diesel engine is operating under a normal load with low firing pressures and high exhaust temperatures. The most probable cause of this condition is __________.

Question 1 of 27070

Q

A diesel engine is operating under a normal load with low firing pressures and high exhaust temperatures. The most probable cause of this condition is __________.

🔍 Key Concepts

• Relationship between firing pressure and how much/when fuel burns in the cylinder • How air flow in and out of the engine (intake vs exhaust) affects exhaust temperature • Effect of fuel rack position on fuel quantity and resulting cylinder pressure/temperature

💭 Think About

• If firing pressure is low, what does that tell you about peak combustion pressure and how efficiently the charge is burning in the cylinder? • High exhaust temperature usually means a lot of heat is leaving unconverted in the exhaust — what engine condition would cause more burning to occur late in the stroke or even in the exhaust system? • Compare what happens to firing pressure and exhaust temperature when you give the engine too much fuel, too little fuel, or restrict the flow of exhaust gases.

✅ Before You Answer

• For each choice, decide: does it tend to make firing pressure go up or down? • For each choice, decide: does it tend to make exhaust temperature go up or down? • Look for the option where both effects line up with the symptoms: low firing pressure AND high exhaust temperature.