Define over-throttling.

Define over-throttling.

• A. Process of injecting or supplying the diesel engine with more fuel than can be burned
• B. Process of cooling the engine excessively
• C. Process of reducing fuel flow during acceleration
• D. Process of recirculating exhaust gas

Answer: (A)

Over-throttling happens when more fuel is injected into a diesel engine than can be burned with the air that’s available for combustion. In diesels, air intake largely sets the amount of oxygen for burning fuel, and fuel delivery is matched to that air. If you push in more fuel than the air can support, some of it won’t burn, leading to unburned fuel in the exhaust, visible smoke, wasted fuel, and potential performance issues. The other options don’t describe this condition: cooling the engine excessively isn’t about fuel-for-air balance; reducing fuel flow during acceleration is under-fueling, not over-fueling; recirculating exhaust gas is an EGR process, not throttling.

Over-throttling happens when more fuel is injected into a diesel engine than can be burned with the air that’s available for combustion. In diesels, air intake largely sets the amount of oxygen for burning fuel, and fuel delivery is matched to that air. If you push in more fuel than the air can support, some of it won’t burn, leading to unburned fuel in the exhaust, visible smoke, wasted fuel, and potential performance issues. The other options don’t describe this condition: cooling the engine excessively isn’t about fuel-for-air balance; reducing fuel flow during acceleration is under-fueling, not over-fueling; recirculating exhaust gas is an EGR process, not throttling.