🔍 Key Concepts

• constant-stroke fuel injection pump design and what stays the same vs. what changes • how fuel quantity is controlled in a jerk-type (individual) injection pump • difference between a control device and components that mainly affect sealing, timing, or speed control

💭 Think About

• On a constant-stroke pump, if the plunger stroke does NOT change, what part of the system can still change the amount of fuel sent to the injector each cycle? • Which listed component is directly linked along the length of several pumps on a multi-cylinder engine and is moved by the governor to increase or decrease fuel? • Think about which parts mainly affect pressure sealing and return flow (delivery valve), engine speed sensing (governor), or mechanical connection (crossbar), versus the part that actually adjusts the pump’s metering position.

✅ Before You Answer

• Identify which option is the main metering control element in a jerk-type injection pump, not just a related component. • Ask: which component is physically shifted to rotate or reposition the plungers’ helical ports to change fuel quantity while leaving stroke constant? • Eliminate any option whose primary job is speed sensing, non-return/pressure maintenance, or simple mechanical linkage rather than metering control.