Because it relates so directly to performance of the vehicle, one job that's particularly rewarding for the automotive do-it-yourselfer is an engine tune-up. In modern vehicles, the recommended interval between tune-ups may be as much as 100,000 miles. Before the era of computer-controlled engine systems and advance synthetic lubricants, however, those intervals were more in the range of once per year or every 12,000 miles. If you've got an older or classic vehicle that you want to keep in peak running condition, treat it to a tune-up at least as frequently as was recommended at the time that the vehicle was built. To perform a thorough tune-up, you'll need a variety of replacement parts (figure A) including spark plugs, spark-plug wires, points, rotor-button, condenser, distributor cap, vacuum-advance and PCV valve. It's also a good idea to go ahead and replace the engine air-filter at tune-up time. Materials:
Replacement parts including plugs, wires, points, rotor, condenser, etc. (see above)
Vehicle service manual
Timing light and timing-light instruction manual
Socket wrench
Torque wrench
Spark-plug gapping tool
Feeler gauge
Screwdrivers, nut-driver
Antiseize lubricant
Dielectric grease
As with any automotive project that involves electrical parts or wiring, disconnect the vehicle's negative battery cable before you begin, in order to avoid injury or damage to the electrical system. - Remove the air-filter housing to provide access to the top of the engine.
Tip: With the filter-housing removed, the top of the carburetor will be exposed. Place a rag over the opening of the carburetor to prevent small objects from falling in.
- Pull the spark-plug wires loose from the plugs and use a socket wrench to loosen and remove the old spark plugs (figure B). Be careful anytime that you are removing or installing spark plugs so as not to damage the threads in the engine block.
- Compare the old plugs with new ones (figure C) and inspect the old plugs, paying particular attention to the electrode for signs of damage, scoring or carbon buildup. The condition of the plugs is a reliable indicator of how well your engine is operating. Consult your vehicle's service manual for information on diagnosing engine problems by condition of the plugs.
- To ensure proper electrical contact, gap each new spark plug using a gapping tool (figure D). Check your vehicle's service manual for the proper gap width. A properly gapped plug will provide a slight drag on the tool's blade that corresponds with the specified gap-width.
- Once you've gapped all the plugs, install them and use a torque wrench to tighten them to the proper torque specifications, according to the service manual. Use a small amount of antiseize lubricant on the threads of each plug. This will make them easier to install and will help ensure that the heat of the engine won't cause them to stick, making it difficult to remove them at a later date.
- Use a screwdriver to loosen the screws holding the distributor cap in place, and carefully lift the cap off the distributor (figure E). Leave the old spark-plug wires connected to the distributor cap until you are ready to replace them. With the distributor cap removed, inspect the distributor assembly and locate the rotor button (figure F), the breaker points and the condenser (figure G).
(NOTE: The parts are identified in the figures f and g with the screwdriver serving as a pointer.)
- Remove the rotor button. It lifts off easily.
- Unplug the wire leading from the coil to the breaker points, then carefully remove the retaining screw holding the breaker in place and lift it free (figure H).
- Carefully remove the retaining screw holding the condenser in place (figure I) and remove it.
- Remove the hose from the vacuum advance, unscrew and remove the screw holding the vacuum advance in place (figure J) and remove the vacuum advance.
- Install the new vacuum advance and reattach the hose.
- Install the new condenser (figure K) and new breaker points (figure L).
- Reattach the condenser wire and the hot wire that leads to the coil.
- Use a feeler gauge to ensure the proper gap between the points (figure M) in accordance with the specifications in the vehicle service manual.
- Reinstall the rotor button.
- Install the new distributor cap, making certain that it is oriented in the same way as the original one (figure N).
- Install the new spark-plug wires. Since you haven't yet removed the old spark-plug wires from the distributor cap, it will be easy to make certain that you connect each plug to the proper contact on the distributor cap. Each spark-plug wire is a different length, which also helps prevent confusion about which wire goes with which contact. Use a small amount of dielectric grease in the boots on the ends of the wires as well as on the contacts.
- Once you've completed installation of all of the parts, reconnect the battery, start the engine and take the vehicle for a test drive.
- The final step is to check the ignition timing with a timing light (figure O) -- a specialized tool that offers the most accurate method of checking the timing on nonelectronic ignitions. Correct ignition timing means that voltage is being properly regulated so that each spark plug is firing at exactly the proper instant. The timing light connects to the spark-plug wire providing spark to one of the engine cylinders (usually cylinder #1). With the engine running, the light strobes each time current is sent to the designated cylinder. There are timing marks on the crankshaft pulley that rotates when the engine is on. If the timing light is pointed at the pulley while the engine is running, the flashing light will illuminate the timing marks in such a way as to indicate whether the timing is properly adjusted. Read and follow all instructions that come with your timing light to use it properly when checking your vehicle.
RESOURCES :
Auto Repair for Dummies
Author: Deanna Sclar
ISBN: 0764550896
Professional Tips and Techniques for Tune-Up and Electrical Service
Model: 1879110156
Author: Michael Bishop and Dennis Holmes
To order this title from Amazon.com, click here.
Do-It-Right Publishing
New Hall, CA 91322
Standard Guide to American Muscle Cars
Model: 0873412303
Author: John A. Gunnel, editor
(2001)
To order this title from Amazon.com, click here.
Krause Publications
Website: www.krause.com
| 
)
)
)
)
)
)
)
)
)
)
)
)
)
)
)
WINDOWS MEDIA VIDEO
