Inline Pumps

Question 1

How is a multiple plumber injection pump timed

Answer 1

Through a camshaft

Question 2

How is a multiple plunger injection pump metered

Answer 2

Metered by the governor. Govner is connected to the control rack

Question 3

Is it true that the multiple plunger injection pumps are PLN fuel systems?

Answer 3

Yes they are pump line nozzle fuel systems

Question 4

Why isn’t the multiple plunger injection system used today?

Answer 4

Wouldn’t be able to keep uo with today’s emissions standards

Question 5

What is the maximum injection pressure of a inline pump

Answer 5

19,500 psi highest
Lowest is 8250 psi
8250-19,500 is the range

Question 6

What is a fill and spill port

Answer 6

These ports are located 180° apart. As your plunger moves up and down the barrel it will be open to the fill port, injection happens when just the fill port is open and pressure can build up, once the spill port opens pressure decreases and injection ends

Question 7

What is a control groove

Answer 7

Control groove or helix is the spiral shape that the plunger has to help control metering.

Question 8

If your barrel or plunger is worn out can you just replace one without the other?

Answer 8

No you have to replace them as a pair

Question 9

What does the pinion gear do

Answer 9

Meshes with the control rack

Question 10

When the fill and spill ports are above the plunger what happens

Answer 10

Fuel is free to flow through the fil and spill port. This ensures fuel is always in the barrel

Question 11

What is effective stroke

Answer 11

The distance the plunger moves between the fill port closing and the spill port opening. The amount of time fuel is pressurized in the barrel.

Question 12

What is start of delivery

Answer 12

This is the point of which the plunger moves past the fill and spill ports and starts to pressurize on its upward stroke. Fuel is delivered to the nozzles at high pressure for injection

Question 13

What is lift to port closure

Answer 13

Position where the plunger begins to cover the spill and fill port. Considered the beginning of injection event when adjusting the pump to engine timing

Question 14

What is injection

Answer 14

This is when fuel pressure lifts the delivery valve from its seat delivering fuel to the injector

Question 15

End of delivery is what

Answer 15

When the spill port opens up and pressure drops

Question 16

To shut off the engine what occurs

Answer 16

The control rack rotates the plungers to a position where the spill and fill ports are aligned not allowing fuel pressure the build up which prevents any pressurization of the fuel for delivery

Question 17

What do retard notches do

Answer 17

Retards timing for cold start ups. Causes fuel to be spilled longer as the plunger moves upwards. Usually ten degrees of crank rotation delaying beginning of injection.

Question 18

Autimatic timing mechanisms

Answer 18

Located between pump drive mechanism and geartrain
Uses centrifugal weights and springs.
As engine rmp increases timing is advanced

Question 19

What is injection lag

Answer 19

Delay of injection

Question 20

What is a delivery valve

Answer 20

Located at outlet of plunger and barrel assembly
Consists of a spring, seat and a specifically designed valve.
Prevents fuel dribbling and injection lag

Question 21

To minimize effect of pressure wave reflections what shape does the delivery valve have built into it?

Answer 21

The delivery valve has a retraction function built into its shape to prevent pressure wave reflections (secondary injections)

Question 22

What is static timing?

Answer 22

Pump timing that is adjusted when an engine is stopped
Static-stopped

Question 23

What is dynamic timing

Answer 23

Changes in pump timing when an engine is running