Worksheets7290-157 Lesson 7 CRDi
Total questions: 10
Worksheet time: 5mins
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
