Title: Engine Tune-Up
1Engine Tune-Up
By Jonathan Rollins
2 - Tune Up Procedures are done as part of a
routine maintenance rather than to correct a
drivability problem.
3Wear safety glasses!
4Spark plug replacement
- Most new engines do not require spark plug
replacement for up to (100,000 miles)
5Normal service and replacement items in a minor
tune-up are
- Perform a visual inspection for obvious problems
- Check for trouble codes on computer controlled
vehicles - Replace spark plugs
- Service the ignition system, including checking
secondary components - Replacing the air and fuel filter
- Changing oil and lubricating the chassis
- Testing and servicing emission control system,
and resetting the reminder circuit - Adjusting the fuel system if applicable
- Cleaning the throttle body and idle air bypass on
fuel injected engines - Road testing before and after tune-up to check
engine performance
6Service and replacement items in a major tune-up
are
- Perform a scope analysis of engine system
- Testing and replacing spark plug wires
- Testing and replacing fuel pump
- Replacing drive belts
- Replacing brake, transmission, and other fluids
- Replacing or rebuilding the throttle body
- Rebuilding or replacing the distributer
- Adjusting the valve train (some engines)
- Replacing weak sensors oxygen sensor, cam
position sensor, crank shaft position sensor, ect
7Six of the diagnostic tools used during a tune-up
are
- scan tool, an exhaust gas analyzer, a compression
gauge, a multi meter, an oscilloscope, a vacuum
gauge, and other tools
8Some performance factors affected by a tune-up
are
- Engine power acceleration
- Fuel consumption
- Exhaust emissions
- Smoothness of engine operation
- Ease of starting
- Engine service life
9General Tune-Up Rules
- It is important to gather engine and vehicle
performance info before performing the tune-up
because this gives you clues on what you need to
investigate or replace.
10- It is important to bring the engine up to full
operating temperature prior to diagnosing an
operating condition because when the engine is
cold you cannot obtain accurate test results.
11- Its important to maintain a vehicles service
records because if a problem occurs you can check
your record to correct the trouble.
12Tune-up safety rules
- It is important for the battery to be
disconnected before maintenance so it does not
accidentally crank the engine or electrical fire.
13Tune-up safety rules to follow
- Wear eye protection
- Set parking break
- Place vent hose on exhaust pipe
- Disconnect battery
14Typical tune-up procedures
- Battery problems-dirty case top, corroded
terminals, and physical damage - Air cleaner problems clogged or contaminated
filter, inoperative air flaps or disconnected
vacuum hoses. - Belt problems- looseness, fraying, and slippage.
- Low fluid levels- engine oil, brake fluid, power
steering fluid, ect. - Deteriorated hoses- hardened or softened cooling
system, fuel system, and vacuum hoses. - Poor electrical connections-loose or corroded
connections frayed, pinched, or burned wiring
and terminals.
15Three important steps in replacing spark-plug
wires are
- To remove the spark-plug, first check that the
spark-plug wires are numbered or located
correctly in their clips. Grasping the spark-plug
wire boot, pull the wire off the plug. Twist the
boot back and forth if it sticks Ignition coils
must be numbered before plugs can or located
correctly in their clips. grasping the spark-plug
wire boot, pull the wire off the plug. Twist the
boot back and forth if it sticks. Ignition coils
must be removed before plugs can be replaced. Be
sure engine is cool before removing spark-plugs.
Removing a spark-plug from a warm aluminum head
can damage the threads in the spark-plugs holes.
16Tools used to remove spark-plugs
- Swivel ratchet, an extension, and a spark plug
socket.
17The correct colors for the tip and insulator
- Grayish or brown properly burning
- Black or wet not firing or engine problem
18- If the spark-plug wire is not put on the right
cylinder spark-plug, the plug will not fire.
19Oxygen sensors
- One and two wires need to be replaced at
50,000-60,000 miles - Heated three-wire oxygen sensors should be
replaced at about 100,000 miles
20Recommended procedures for replacing a sensor
- Disconnect the negative battery cable. then,
separate the sensor from the wiring harness by
unplugging the connector. Never pull on the wires
them selves, as damage may result.
21Three primary adjustments performance during a
tune-up
- Pick up coil air gap adjustment
- Idle speed adjustment
- Ignition timing adjustment
22Diesel engine tune-up
- Diesel engines require periodic maintenance
similar to gasoline engines but dont have spark
plugs to replace or an ignition system.
23Typical service tasks performed during diesel
engine maintenance intervals are
- Replacing the air filter element
- Cleaning, draining, or replacing the fuel filters
- Adjusting engine idle speed
- Adjusting accelerator and governor linkage
- Inspecting the engine and related systems
- Adjusting valve and injector timing
- Changing engine oil and oil filter
- Servicing emission control systems
- maintenance intervals are specific periods ( in
miles or months ) for component service.