190203f Basic Diesel And Fuel System Testing And Adjusting Flashcards
What are the effects if injector nozzles are not operating properly
Hard starting
Rough idle
Low power
White or /black smoke
What to operating conditions may affect the tuneup interval for an engine
The type of engine and the application
How would you do a cylinder balance test ( injector cut out)
By momentarily loosening ( cracking) fuel injector line connection
By useing a infrared thermometer to check for misfiring where should you check at ?
and what is maximum temperature drop?
At exhaust port
No more than 50 degres
Dynamometer are used for ?
engine performance testing, diagnosis, trouble shooting and break-in after rebuild
With kind of engine conditions are you able diagnose with a dynamometer ?
misfiring cylinders
operational noise
vibration
crankcase pressure (blowby)
Two operating conditions that may affect the tune-up interval for an engine are…
Type of engine load
Application
What are three benefits of a properly tuned engine?
Low emissions
Most efficient engine operation
Maintained horsepower
List three conditions of an engine that may require a tune up
Mechanisms have been disturbed for repairs
Poor engine operation
Part of scheduled maintanence
How does excessive valve clearance affect an engine?
It causes retarded timing and reduced valve opening, causing poor engine performance
When you perform adjustments to a governor, what condition must the engine be in?
Warmed up to operating temperature
What should you check before performing governor adjustments?
You should check the throttle linkage condition for play and proper adjustment
True or false. On a diesel engine, a timing light is triggered by an electrical pulse generated in the injector line.
False. It operates on the high pressure pulse of the line expanding during each injection.
To isolate a faulty fuel injector on a running engine, momentarily crack the line on each injector and note the RPM drop, OR…
Check the temperature drop between the exhaust ports.
True or False. The fuel injector needle opening pressure cannot be adjusted on any type of injector. If incorrect, the injector must be changed out.
False. On most hydraulic injectors you can adjust opening pressure by installing shims or via the adjustment screw.
How do you check for fuel injector needle seat - to - face leakage? (dribble)
Watch for fuel seepage at the nozzle tip while the injector is under pressure.
True or False. When you test a multi-hole fuel injector, the spray pattern is evenly generated by all of the spray hole orifices in the nozzle.
True
What does a dynamometer do?
It absorbs and measures the power output of an engine. It allows you to test performance and simulate load conditions on the engine.
What are the three basic components a Dynamometer
A power absorption device (load cell), a load control and a torque measuring device
What are the two functions water has in a water brake type dynamometer.
Cooling and load control
List three engine/vehicle sources from which dynamometers can measure power
Off the engines flywheel, from the vehicles rear wheels, off the PTO shaft of a tractor
What is the formula for horsepower
Torque times RPM over 5252
What are three things you should do when using a dynamometer regarding personal safety
Wear PPE, avoid rotating equipment and tie up longhair
True or false. A vehicle on a chassis type dynamometer must be placed squarely on the rollers and be properly chained and blocked before the vehicle is operated
True
