MDE 5 End of Unit Quiz

MDE 5 End Of Unit Quiz

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4. Effects of Fuel Pressure on Nozzle Operation

Question: How does high fuel pressure affect the operation of a diesel engine fuel nozzle?

B) It increases the spray pattern's spread and improves atomization

D) It reduces the overall fuel flow rate

C) It lowers the fuel temperature before injection

A) It decreases the spray pattern's spread

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Defects in Main Engine Fuel Injectors

Question 1: What is a common defect in fuel injectors that results in poor engine performance and increased exhaust smoke?

B) Leaking fuel lines

A) Clogged nozzle orifices

C) Worn piston rings

D) Faulty glow plugs

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Preventing Fuel Spray from High-Pressure Pipe Failure in Scroll Type Fuel Injection Pumps

Question: In scroll type fuel injection pumps, how is fuel oil prevented from spraying out if the high-pressure pipe fails in service?

C) By incorporating a shut-off valve in the pump assembly

D) By utilizing a design that allows fuel to bypass the high-pressure pipe

B) By employing a safety valve that closes off the fuel supply

A) By using a pressure relief valve to divert excess fuel

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Varying Delivered Quantity in Scroll Type Fuel Injection Pumps

Question: In scroll type fuel injection pumps, how is the delivered quantity of fuel varied?

C) By modifying the position of the scroll or cam mechanism

B) By changing the angle of the delivery valve

A) By adjusting the rotational speed of the pump

D) By altering the temperature of the fuel

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Fuel Metering in Scroll Type Fuel Pumps

Question: How does a scroll type fuel pump meter fuel for high and low loads?

B) By changing the position of the camshaft

A) By adjusting the speed of the scroll mechanism

C) By varying the displacement of the scroll mechanism

D) By altering the temperature of the fuel

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Purpose of the Delivery Valve in Bosch or Jerk Type Fuel Injection Pumps

Question: What is the purpose of the delivery valve in Bosch or Jerk type fuel injection pumps?

A) To regulate the fuel pressure before injection

C) To control the timing of fuel injection

D) To filter impurities from the fuel before it enters the pump

B) To prevent fuel leakage back into the pump after injection

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Question 3: What defect can lead to erratic engine operation and knocking?

B) Overheating of the fuel pump

D) Damaged air filter

C) Faulty engine thermostat

A) Incorrect spray pattern

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Purpose of the Delivery Valve in Scroll Type Fuel Injection Pumps

Question: What is the purpose of the delivery valve in scroll type fuel injection pumps?

A) To regulate the fuel pressure before it enters the pump

D) To filter contaminants from the fuel before it reaches the injector

B) To control the timing of the fuel injection

C) To prevent backflow of fuel from the high-pressure side to the low-pressure side

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Defects in Diesel Engine Fuel Nozzles

Question: What are some defects that diesel engine fuel nozzles may encounter during service? (Select THREE)

A) Clogged nozzle orifices

F) Overheating of the fuel pump

E) Incorrect spray pattern

B) Leaking nozzle seals

C) Excessive fuel pressure

D) Corrosion or erosion of the nozzle tip

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5. Common Issues with Diesel Fuel Nozzles

Question: What is a common issue that can affect the performance of a diesel engine fuel nozzle?

A) Clogged nozzle orifices

C) Worn-out spark plugs

B) Excessive engine coolant pressure

D) Dirty air filter

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Main Components of a Fuel Injector Nozzle

Question: What are the MAIN components found in a cross section through the nozzle of a fuel injector? (Select THREE)

E) Spring

B) Solenoid coil

A) Nozzle tip

C) Needle valve

D) Fuel filter

F) Injector body

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Understanding Penetration

Question: What does the term "penetration" refer to in the context of diesel engine fuel injection?

C) The width of the fuel spray pattern

A) The depth to which fuel droplets penetrate into the combustion chamber

B) The distance the fuel travels through the fuel lines

D) The speed at which fuel is injected into the combustion chamber

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