Fuel Injection Flashcards
What are the differences between direct and indirect fuel injection
Direct - less economical, more powerful, starts unaided, lumpy
Indirect - more economical, cleaner exhaust, cold start assisted, smooth
Why sort of pressure is in a diesel injector?
200+ bar
What are the 3 types of heater plugs?
External, internal and micro nova
In a basic diesel fuel system what are the main components?
Fuel tank Fuel lift pump Filter Sedementor Injection pump Injectors
What controls engine speed?
A governor
In the fuel system what dose the low pressure side do?
Cleans the fuel and delivers to high pressure side
What dose a governor do?
Control how much fuel goes from injection pump to the injectors
What are the types of nozzle on an injector?
Single Hole
Multi hole
Pintle
With injectors. The hole type, the multi hole type.
How many whole are there and what size?
Up to 12 holes starting at 0.2mm
What dose white smoke mean?
Incorrect fuel pump timing
Leaking cylinder head gasket
Poor compression
What dose blue smoke mean?
Lubricating oil is being burnt
What can cause good combustion ?
Squish and swirl of the fuel
What pressure is a indirect injection?
100 to 150 bar
What does the fuel pump do?
Convers the fuel to low pressure to high pressure,
Transfers the fuel to the injectors
What does a baffle do?
Allows no oxygen into the pick up, always submerged in fuel
What are 2 fuel lines used for?
To carry fuel to the injectors
To carry fuel back to the tank
What are the 3 types of lift pumps?
Diaphragm
Plunger
Vein pump
What acts on the rocker arm in a diaphragm fuel pump?
Eccentric cam
What does a fuel filter do?
Removes any abrasive particles and water to reduce any damage to the engine
What are the types of fuel filters
Sedimenter unit
Resin impregnated paper filter
What’s aids cold starts?
Coolant heaters Oil heaters Battery warmers Glow plugs and intake heaters Fluid starting aids
What circuit do glow plugs operate on?
Parallel and series
How does an injector work?
Pump pressure operates the nozzle against the injector spring, nozzle valve opens and closes many times rapidly each injection
Where does pintle get commonly used ?
Indirect injection.
What does black some indicate ?
Fuel is only being partially burnt
Restriction in air intake
Failure to atomise
Poor compression/valve timing
What are the types of governors ?
Mechanical
Hydraulic
Pneumatic
