Which of the following will occur when the...

Which of the following will occur when the...

Question 1 of 270705eccefa2bacbc34ba4d478a1

Which of the following will occur when the lower edge of the spiral, on the plunger of a jerk pump, uncovers the spill port?

Question 1 of 27070

Q

Which of the following will occur when the lower edge of the spiral, on the plunger of a jerk pump, uncovers the spill port?

🔍 Key Concepts

• Jerk pump fuel cycle – how fuel is pressurized and then released • Spill port and plunger spiral (helix) – what uncovering the port changes inside the pump • Difference between plunger motion and fuel flow/pressure

💭 Think About

• Think through what happens to the fuel pressure inside the pump barrel at the exact moment the spill port is uncovered by the spiral on the plunger. • Ask yourself: does uncovering the spill port change the plunger’s movement, or does it change what happens to the fuel around the plunger? • Consider how the pump stops injection at the end of the effective stroke – what component action actually ends fuel delivery to the injector?

✅ Before You Answer

• Verify what ‘spill port’ means in a jerk-type fuel injection pump and what it is connected to. • Clarify whether the plunger’s direction of travel depends on the spill port, or on the cam driving the plunger. • Check how uncovering the spill port affects pressure in the pumping chamber and, as a result, fuel delivery to the injector.