7290-157 Lesson 7 CRDi

On a mechanical diesel injection system what is the operating pressure

• 45 BAR

• 180 BAR

• 2500 BAR

• 3 BAR

On a CRDi engine how are the injectors 'fired' ?

• Piezo-electric pulse from an ECU

• Once fuel pressure reaches limit valve lifts

• Electronic Solenoid switched by ECU

• Use of a timing pump, delivering each injector

which of these is not a benefit of Piezo-electronic injectors?

• Better fuel atomisation

• Reduced engine noise

• Fuel is directed into inlet port

• Up to six injections per stroke

Which component listed is a low pressure item?

• Fuel pump on engine

• Fuel rail

• Fuel injectors

• Fuel pump in tank

What is component arrowed?

• Piezo actuator pack

• Nozzle module

• Control valve

• Coupling module

How many phases of CRD are there in the delivery steps?

• six

• one

• three

• two

What are the three delivery phases known as?

• Pilot, Pre, Post

• Pilot, Main, Post

• Main, eco, boost

• Heat, main, regen

What is the process triggered between 40° and 90° BTDC?

• Post Injection

• Main Injection

• Pilot Injection

• Re-generation

What is not a benefit of higher fuel pressures?

• higher fuel consumption

• Less unburnt fuel

• More power

• better air fuel mix

What is purpose of glow plugs after starting in a CRD engine?

• To aid fuel air mixing

• to ignite the atomised fuel

• to heat air before it enters cylinder

• to reduce soot particles