When restarting a heavy fuel diesel engine...

🔍 Key Concepts

• Heavy fuel oil (HFO) characteristics such as viscosity, ignition quality, and need for heating/conditioning • How starting and combustion are affected when an engine and fuel system have been idle and cooled down • What parameters (air, speed, injection pressure, or fuel properties) engineers can safely and practically adjust during starting

💭 Think About

• Think about what happens to heavy fuel in the lines and injectors when the engine sits stopped for a while. Does it get thicker or thinner? Easier or harder to ignite? • Which of the listed options is a normal, practical operational adjustment during a restart, and which would require design changes to the engine or fuel system? • Ask yourself: which choice directly helps ignition of cold, heavy fuel in a way an engineer can realistically control before or during start-up?

✅ Before You Answer

• Verify which options would require equipment redesign (e.g., different injectors or starting system) versus a simple operational procedure change • Consider standard practice: is it usual to change starting air pressure or fuel injection pressure just because the engine has been stopped? • Check which factor most directly improves ignition of cold heavy fuel without risking damage or operating outside normal limits

When restarting a heavy fuel diesel engine that has been stopped for some time, the engineer should __________.

increase the starting air pressure

use a higher than normal cranking speed

increase the fuel injection pressure

use a fuel having a lower ignition temperature

🔍 Key Concepts

💭 Think About

✅ Before You Answer