Engine tuneup
M
aking the Exit. Timing is Everything.
The weather is nice and you’re zipping along down the highway’s left lane making good time. Between looking at the cloudless sky and fumbling with the radio, you notice that your exit is rapidly approaching. Traffic isn’t too bad on Sunday morning, and there is a break in the traffic flow. You put on your signal and start to merge off.
You apply sudden pressure on the gas but then a scary image fills your mirror. A pale blue 1976 Ford Pinto just beat your big V-8 to the spot. It was behind you and then was quickly able to move into the hole faster than you. The Pinto’s driver flashes you a cheesy grin as he exits. You try to quell your anger while driving the next 42 miles to make a U-turn before your 4 kids take notice.
Your wife turns to you with saucer wide eyes in utter disbelief. The "Are we there yet?" coming from the back seats reverberate around the cabin for an additional hour. In a moment of silence your wife recommends it may be a good idea to get the car tuned-up. You look down and your digital dash and wonder if today’s computerized cars need tune-ups?
Wonder no more. Today’s cars still need engine care. It may be true that the recommended intervals between tune-ups may be as much as 100,000 miles, but before the advent of synthetic lubricants, 100,000 miles spark plugs, and non replaceable fuel filters the interval was closer to 12,000 miles. If you have an older vehicle, usually pre 2001, that you want to keep in optimal condition, perform a tune-up at least once a year.
Performing a tune-up is a bit like surgery. You need the correct tools to do the job correctly. You’ll need a variety of replacement parts including spark plugs, spark-plug wires, points, rotor-button, condenser, distributor cap, vacuum-advance and PCV valve.
Materials:
Replacement parts including plugs, wires, points, rotor, condenser, etc.
Screwdrivers, nut-driver
Vehicle service manual
Timing light and timing-light instruction manual
Socket wrench
Torque wrench
Spark-plug gapping tool
Feeler gauge
Anti seizing lubricant
Dielectric grease
Before you begin, as with any automotive project that involves working with the electrical system or wiring, disconnect the vehicle's negative battery cable. Getting a good shock is not as fun as you may think. Disconnect the cable will help you avoid injury or damage to your or the electrical system.
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Remove the housing for the air-filter to provide access to the top of the engine.
Hint: With the filter-housing removed, the top of the carburetor will be exposed. Place a clean rag over the opening of the carburetor to prevent any small objects or moisture from entering it. - Pull the spark-plug wires loose from the plugs and use a socket wrench to loosen and remove the old spark plugs. Don’t just reach down and yank them out like you are pulling weeds in your yard. Take your time when you remove and install spark plugs. Take care not to damage the threads. Retooling threads on an engine block is extremely difficult and expensive.
- Hold the old and new plugs side by side. Pay attention to any signs of damage to the electrodes of the old plugs. Is there damage, scoring or carbon buildup? The condition of your plugs says a lot about the running condition of your engine. Refer to your owner’s manual for information about diagnosing engine problems from the condition of the spark plugs.
- To make sure that your plugs have the proper contact gap each plug with a gapping tool. Check the service manual on what the specifications are for recommended gap width. If there is a slight drag on gapping tool when you slide it out then it’s a good gap.
- Once you've gapped all the plugs, install them and torque them with a torque wrench to the proper specifications, according to the service manual. Apply a small amount of anti-seizing lubricant on the threads of each of the plugs. The lubricant ensures that the heat of the engine won’t cause them stick. It also makes it easier to remove them in the future.
- The distributor cap is removed by using a screwdriver to loosen the screws holding it in place. Carefully lift the cap off of the distributor. Don’t remove the old spark-plug wires connected to the distributor cap unless you are going to replace them. With the cap removed, locate the rotor button and inspect the condition of the distributor assembly, breaker points, and the condenser.
- Remove the rotor button. It easily lifts off.
- Locate and unplug the wire going from the coil to the breaker points. Carefully remove the screws that retain the breaker in place. Lift it free.
- Remove the condenser by carefully removing the retaining screws.
- Disconnect the hose and unscrew the screws holding the vacuum advance and remove.
- Install the new vacuum advance and reattach the hose.
- Install the new condenser and new breaker points.
- Reattach the hot wire that leads to the coil and the condenser wire.
- Use a feeler gauge to ensure the proper gap between the points are in accordance with the vehicle service manual specifications.
- Reinstall the rotor button.
- Install a new distributor cap and make certain it is situated the same way as the original one.
- Install the new spark-plug wires. Each spark-plug wire is a different length so it is relatively easy to install them in the correct order. Refer to the old cap to prevent confusion as to which wire goes where. Add 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 the reassembly and installation of all the parts, reconnect the battery, start the engine, and get out on that highway again.
- The final step of your tune-up is to check the ignition timing by using a timing light. This specialized tool indicates if voltage is being properly regulated to each spark plug and that the plug is precisely firing. The timing light connects to one of the spark-plug wires (usually cylinder #1). While the engine is running, the light strobes each time current is sent to the cylinder. The crankshaft pulley has timing marks that rotate when the engine is on. When the timing light is pointed at the pulley while the engine is running, a flashing light illuminates the timing marks to indicate if the timing is properly adjusted. Completely read all your timing lights instructions and follow them so that you can make that exit the next time.
The will is never free - it is always attached to an object, a purpose. It is simply the engine in the car - it can't steer.
- Joyce Cary
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