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178 Cards in this Set

  • Front
  • Back
What do the connecting rod and crankshaft do?
Convert reciprocating motion into rotary motion.
What are the two kinds of holes in a crankshaft?
1) Oil transfer holes in the bearings
2) Balancing holes
Name the strokes in a four-stroke cycle engine.
1. Intake
2. Compression
3. Power
4. Exhaust
What are connecting rod bearing characteristics?
1. Load strength
2. Antiscuffing
3. Corrosion resistance
4. Conductivity
5. Insensitive to temperature change
6. Embeddability
7. Conformation
What are some ways piston expansion is prevented?
1. The use of steel struts
2. Cam-ground piston
3. Partial Skirt Pistons
4. Split Skirt Pistons
5. T-Slot Pistons
List 3 ways camshafts are driven
Gears, timing chain, or timing belt.
What is the ratio of crankshaft to camshaft rotation?
What are the two types of piston rings?
Compression rings and oil control rings.
What are the two types of springs on clutch discs?
1) Wave springs - providing a range of smooth engagement
2) Torsion springs absorb twisting force
What types of connections exist between pedal and clutch fork to activate the clutch?
Cables, pushrod linkage, and hydraulic
What are problems associated with incorrect free play in the clutch pedal?
Too much - might grind gears due to insufficient clutch engagement.
Too little - might cause throwout bearing wear as it is constantly engaged.
What touches the clutch disc?
Pressure plate, flywheel, transmission input shaft.
What touches the pressure plate?
Flywheel, clutch disc, throwout bearing.
What 3 parts are needed to convert 2wd to 4wd?
Transfer case, front driveshaft, steering differential.
What are the 2 jobs of the transfer case?
Transmit power to front wheels, select driving range.
What are the four modes available from a planetary gearset?
Overdrive, direct drive, reverse, low.
What components do the shifting in an automatic transmission?
Clutches and bands.
Where does automatic transmission get oil pressure?
Transmission oil pump.
What does the oil pump do in an automatic transmission?
Lubricates transmission, engages clutches and bands.
What does the valve body do?
Up to 4-5 housekeeping tasks associated with each shift command from the shift valves.
What actuates bands in an automatic transmission?
What releases clutches in an automatic transmission?
Where does an automatic transmission get its shift information from?
Governor and throttle valve, or VSS and TPS+MAP.
What does transmission look at when deciding when to shift?
Speed and load.
What are the two things a torque converter does?
Increase torque and prevent stall at stop.
When does lockup in a torque converter normally occur?
Over 40mph or so.
When does the oil pump in a transmission turn?
Whenever engine is running or cranking
How do you get oil to a rotating part?
Grooves and seals.
What does lockup give you?
Better efficiency at high speeds.
What is the Governor's job?
Sends speed information to the automatic transmission.
What does a throttle valve do?
Send load information to the automatic transmission.
How many ways are there to do a Limited Slip Differential?
Three, clutch plate, cone clutch, torsen differential.
When driving straight ahead, what do differential gears do?
They tumble.
When do differential pinion gears rotate?
When cornering or whenever one wheel moving faster than the other.
If one tire is in snow, ice, mud, or slime, which wheel gets power in an open differential?
The wheel with no traction.
What are the three jobs of the outboard CV Joint?
Rotate, move up and down, and turn.
What are the three jobs of the inboard CV joint?
Rotate, move up and down, and change length.
What is required to remove a driveshaft?
Remove 4 bolts with a crescent wrench.
When should you remove a driveshaft temporarily?
Before towing.
What activates the clutches in an automatic transmission?
Oil pressure pistons.
What to clutches and bands do in an automatic transmission?
Clutches lock two parts together, bands stop the motion of a part.
When is a synchronizer used?
Whenever entering a new gear.
On what type of transmissions are output gears always spinning?
Both automatic and manual.
What two parts can be eliminated by using a MacPherson strut?
Upper control arm, upper ball joint.
What is the job of the spring in a suspension?
Absorb force of bumps so it's not transmitted to the body.
What is the job of the shock absorber?
Control the spring.
What is brake fade, and how do you tell that it has occurred?
No brake friction due to heat, the brake pedal feels normal, but car won't slow as fast.
How many tie rod ends are there?
What do brakes do?
Convert motion into heat.
What are the advantages of disc brakes?
Self-adjusting, self-cooling, and throw water out.
What are the jobs of gasoline?
Burn cleanly, ignite readily, and resist early detonation.
Why do you want valves to rotate in their seats?
It provides a wiping action that eliminates carbon.
What are three circuit protection devices?
Fuses, circuit breakers, fusible links.
What is a short?
Unintended path to ground.
Why must freon be compressed?
To give up heat to outside air, the freon temp must be much higher than outside air.
How do you check pressure in AC system?
Hook up a pressure gauge.
What are low and high pressure sides of an AC system?
Low pressure is evaporator, high pressure is condensor.
T/F: Anytime there is current flow, there is a magnetic field?
T/F: Anytime there is relative motion between a conductor and a magnet, it generates potential.
What are relays good for?
Conserves wire, can run heavy wires directly to devices, then use low current wires to control relay switch.
Why is it good to keep heavy wires short?
Reduce voltage drops.
What does a transistor do?
Act as a switch and amplify current.
What happens if a sparkplug does not fire?
Air/Fuel mixture does not ignite, goes out tailpipe and increases emissions.
How do spark plugs wear out?
Sharp edges wear down.
What makes a hot or cold plug?
Path from electrode to ground.
How many basic lengths of threads are there for sparkplugs?
What are the major parts of an ignition pattern?
Firing line, spark line, ring, and dwell.
What is the advantage of integrated coils?
No high voltage wires, total control over ignition timing for each cylinder.
Name oscilloscope functions and useful applications.
Raster - stacked on top of each other, check for alignments.

Parade - view all cylinders in a row, check amplitude of firing line.

Single cylinder - check a single cylinder waveform, check for all expected parts.
Why advance timing at higher speeds?
Air/Fuel burns at a constant rate, needs more time than available with quick piston motion.
Why advance timing on a light load?
Leaner mixture burns slow.
What does the fuel injector do?
Make a fine spray pattern of fuel without burning early.
What are the sensors in fuel injection by category?
Moving: Crankshaft position, Camshaft position, Throttle position, Mass Air Flow, Vehicle Speed Sensor.

Temperature: Engine coolant temp, air temperature.

Pressure: Altitude, barometric, manifold.

Other: Knock, Oxygen.
What are Fuel Injection sensors used for?
How long to squirt injectors, secondary is to control ignition.
What do pressure regulators do?
Under load, pressures are increased, keeping injector size constant.
What are the circuits in a carburetor?
Float, Idle, Off-Idle, Main, Power, Accelerator pump, Choke.
What does the venturi do?
It causes a pressure drop as air speeds up.
What do air bleeds do?
Add air to the fuel to premix it.
What does the power circuit do?
It supplements the main jet.
What does the accelerator pump do?
Adds extra fuel when throttle first operated for immediate power.
How do you adjust a carburetor?
Bend linkages as per instructions.
When do you rebuild a carburetor?
When the throttle shaft is worn out.
How do you tell the difference between choke and throttle valve in a carb?
Throttle is precise, choke is loose.
What can you do with a timing light?
Determine TDC, get RPM reading.
How often do you change sparkplugs?
Owner's manual.
How often do you change points?
10-12k mi.
How often do you change ignition wires?
Every four years or so.
What can you do with mechanical stop - converted sparkplug?
Verify TDC.
What can you do with a transformer?
Increase or decrease voltage.
When does coil produce spark?
On disconnect of power to primary.
What does MAP do?
Manifold Air Pressure determines load on engine.
What do electrical systems use instead of centrifugal advance?
They adjust using crankshaft vehicle speed sensor.
Under what conditions would you switch to hot plugs?
Around-town vehicles with dirty plugs, hotter temps will burn off oil but there is a danger of knocking under load.
When does a water pump run?
Whenever engine is running.
What are the 2 jobs of the thermostat?
Fast warmups to get to closed loop state, and regulate temperature.
What flows through radiators?
Air, coolant, ATF.
How do you look at radiator tubes?
Look in cap or radiator hose fittings?
Can you solder just a little bit of a radiator?
No, you must solder the whole thing.
What are the 2 oil rating organizations?
What's in oil?
Detergents, antioxidants, antifoaming, extreme pressure additives, anticorrosion, pour point depressants, and viscosity improvers.
What are the jobs of engine oil?
Lubricate, clean, cool, seal, anticorrosion, antifoaming.
Cylinder leakage test can determine what locations of faults?
Intake, exhaust, block or heads, oil filler tubes.
What does a thermostatic fan on a RWD do?
Limits max for speed/rpm, and disengages fan if temperature is low. It also reduces noise.
How much dirt is in engine?
1/4 tsp for 10k mi. when using syn oil.
What do you do with fumes getting past piston?
PCV draws fumes from engine into intake manifold.
What were the changes made to cars in 1973?
Compression ratio, camshafts, combustion chamber shape, piston shape, thermostat temperature, lead-free fuel, catalytic converters.
What does the EGR do?
Reintroduces NOx to Air/fuel mixture, diluting it and reducing peak temperatures and pressures to reduce additional NOx from being formed. Only does it when needed.
What are "stoves" on old cars?
Bits of sheet metal covering exhaust manifold, meant to heat up intake air for cold starts.
What does a thermostatic air cleaner do?
It heats incoming air to the carbuertors.
How does air injection affect performance?
Not at all, it occurs after exhaust.
How do fumes vent from the gas tank?
They don't, they go into charcoal canister for storage, where they are transmitted under certain conditions back into the A/F mixture slowly.
How many pieces is an oil control ring made of?
2 scrapers, 1 expander.
What touches cylinder head?
Block, valve cover, intake manifold.
How does a hydraulic valve lifter work?
Uses oil pressure to eliminate any play in valve train.
What is highest degree of precision in the engine?
Hydraulic valve lifter.
How do you check cooling system pressure on a hot engine?
Squeeze the hose.
What is the most common beginner mistake on cooling systems?
Overtightening hose clamps.
What can indicate head gasket is blown or head/block is cracked?
Low compression on adjacent cylinders.
What information do you need to interpret a dyno test?
altitude, barometric pressure, engine temperature, fuel temperature, humidity, oil temperature.
How do you detect resistance?
Heat and voltage drops.
What causes NOx byproducts?
High pressure + heat.
What are the ways to test a computer?
Tap-test with fingers, heating, and cooling.
Does EGR work at idle?
How do you test gas cap?
Pressurize and test tank, if leaky CEL comes on.
How is idle speed increased?
Air supplied to intake manifold.
What is bumping engine?
Flicking key to move crank position.
When does throwout bearing spin?
Whenever foot is on clutch.
What do higher temps do to ATF?
Destroy it.
What's most expensive thing in a transmission?
Where is SO4 on a charged battery?
In the fluid.
What 2 things happen if battery left unused?
Sulfate attaches to plates, and may permanently sulfate there.
What are voltage ranges for charged and discharged batteries?
Cold/hot temps yield what voltages?
High / low
How much battery capacity can you lose on a cold day?
Up to 60%.
What are charging voltages?
15.5 cold, 14.5 hot
What is passing on battery load test?
What is wrong with battery at 10V?
Dead cell shorted.
What precautions should one take on initial fill of dry battery?
Make sure to fill cells evenly.
Who uses a marine battery?
Boats, airplanes.
Who uses deep cycle batteries?
Motor homes, trailers.
What is the moving part in an alternator?
Where is all power generated in alternator?
What is the job of the alternator rotor?
Create a moving magnetic field.
What does the starter solenoid do?
Connects battery to starter motor, and moves pinion into engagement with flywheel.
How many amps does a starter use?
Over 100A.
Give parameters for use of starter.
Not >15secs, with 5 minute wait between.
When does starter operate?
Only when cranking.
How many amps does it take to control the rotor field?
What controls the rotor field?
Voltage regulator.
If a cell is filled higher or lower than others with liquid, what happens to it?
Higher - constant undercharge, lower - constant overcharge.
What are 4 jobs of battery vent caps?
Keep acid in battery, give access for filling with water, vapor recovery, flame arresting.
Name the top power consumers.
Starter, A/C heater fan, headlights, brake lights.
What do you get in a tow package?
Bigger alternator, starter, extra oil cooler.
How do you ID a good spark?
You can see and hear it.
What is a trouble light good for?
Fuses, headlights, tailights, NO SENSORS.
What is used to adjust caster and camber?
Slots, shims, eccentric bolts, tapered washers.
Why check steering axis inclination first during alignment?
Check for bent parts.
What causes tire heat?
Excessive speed + load.
How can you tell a front drum brake pad?
It's smaller.
What happens if moisture gets in the brake lines?
It can boil, and you can lose your brakes.
What is common mistake when bleeding brakes?
Forgot to drain fluid from reservoir.
Are some power brakes powered by the power steering pump?
What can tie rods adjust?
Steering wheel centering, toe in/out.
How much can a tire wobble?
1/16th in.
What does an A/C system do?
Removes heat from passenger compartment and gives it up to outer air.
What does a compressor do?
Circulates refrigerant and increases its temperature.
What does the Receiver/Dryer do?
Stores liquid and absorbs water.
What does the condensor do?
Hot freon gas gives up heat to air and becomes liquid.
What does the evaporator do?
Low pressure liquid freon removes heat from air and turns to gas.
What is the job of the ignition coil?
Increases voltage.
What are two timing advance systems used in carburetor systems?
Vacuum + centrifugal.
How do you check A/C hoses?
Feel and check for mushy or hard hoses.
What can go wrong with a water pump?
Bearings or leaks.
What type of engine block is most affected by acidic coolant?
What is a resonator?
Prevents or tones down objectionable sound/noise.
Why is stainless steel used in exhaust systems?
Lasts >100k mi, required by fed govt.
How is exhaust pipe attached?
Rubber hangers
Does exhaust get longer when hot?