Common Rail Fuel Injection

Fill in the blank: ________ is the most recent development in high-pressure injection systems.

• Common rail fuel injection

• Distributor pump system

• Unit injector system

• Mechanical fuel injection

What is the maximum fuel pressure that new technology allows to be managed in common rail fuel systems?

• 37,500 psi

• 25,000 psi

• 15,000 psi

• 10,000 psi

What are two benefits of new technology in common rail fuel systems?

• Increased emissions and reduced fuel efficiency

• Almost no emissions and increased fuel efficiency

• Reduced control of injectors

• Lower fuel pressures

What are the advantages of Common Rail Fuel Systems?

• Low-injection pressures and slow-acting injectors

• High-injection pressures, fast-acting injectors, and electronic controls

• Manual controls and low-emission gasoline engines

• None of the above

In common rail fuel systems, fuel is pressurized regardless of engine speed for optimal fuel efficiency and low emissions.

• True

• False

Higher Pressurization Systems in development could reach more than ______ psi.

• 45,000

• 10,000

• 25,000

• 60,000

Fill in the blank: CR injectors use ________ design, allowing electrical solenoid to trigger servo valve and provide a short duration injection.

• servo-hydraulic

• mechanical

• pneumatic

• piezoelectric

How many injections per combustion cycle could first generation CR injectors produce?

• 1 or 2

• 2 or 3

• 4 or 5

• Up to 8

Fundamentals of Common Rail Fuel Systems Multiple Injection Events True or False: The newer versions of CR injectors can deliver up to 8 injections per combustion cycle.

• True

• False

Fill in the blank: CR injectors change injection discharge volume during each injection event to suit ______ and ______ conditions.

• speed; load

• temperature; humidity

• pressure; altitude

• voltage; resistance