How To: Tune Up Ignition - PartSource: Automotive, Truck Parts & Accessories

How To Tune Up Ignition

Cold morning starts can do a number on your ignition. So now's the perfect time to replace your plugs, caps and rotors to keep your engine starting smooth throughout the hot days of summer.

This is a super easy job, split into 3 parts:

Replacing Spark Plugs
Distributor Cap and Rotor Replacement
Spark Plug Wire Replacement

Some of you can do this stuff in your sleep, but if it's your first time this guide will show you how to do it step by step. And remember, if you need to talk to a Parts Pro, stop by your local PartSource store. They'll be happy to help.

Let's get started (no pun intended).

A few things before you begin

There are different gappers for different spark plugs so ask your Parts Pro for the right spark plug gap tool when you buy your new plugs

If you're not sure about the type of gap you need for your plug, your Parts Pro can help with that as well.

Allow the engine to cool before starting. No need for an explanation there.

If you just rolled back from PartSource and you want to get started right away, inspect and gap the new spark plugs while the engine cools off. Or watch a bit of TV.

And last, in case you need them, you can always get free print outs of specific vehicle instructions and torque specifications from Mitchell on Demand at your local PartSource store.

Make Safety Your Top Priority

Every vehicle is different, so when it comes to maintenance and repairs, always follow the vehicle's owner's manual.

Make sure you've got all your tools and supplies before you begin - the last thing you want to do is go shopping when you've got the car on the jack.

Safety should be your number one priority, so don't smoke, drink alcoholic beverages, or wear a necktie. And watch out for hot objects, sharp instruments, hazardous materials and other potential safety hazards in and around your workspace.

Don't work with a Philips when it calls for flat. Substituting tools can compromise your safety or a vehicle's performance.

And finally, when the fun turns to frustration or if the job requires specialized knowledge beyond your abilities, please do not attempt it yourself. Talk to a Parts Pro or seek the assistance of a professional mechanic or installer. The last thing we want is someone getting hurt.

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Part 1 of 3: Replacing the Spark Plugs
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Cover the front of the vehicle or the fender (depending on which angle you work from) to prevent yourself from damaging the paint. You'd be surprised what buttons or a belt buckle can do to paint.

Disconnect the ground cable on the battery.

Remove the spark plug wires.

REMEMBER: Remove one plug at a time so you know which wire goes where.

Pull on the boot end, not on the wire, using a left-right twisting motion to free the wire from the spark plug. If it still wont come off use a spark plug boot puller tool to avoid damaging the wire.

If you have an air compressor, use it to blow any dirt away from the spark plug area. A common bicycle pump will do the trick as well. You don't want any dirt falling into the cylinder once you remove the spark plug.

Using your spark plug socket, remove the spark plug by turning in a counterclockwise direction.

Now you're ready to install the new plug. If you didn't gap the plugs while the engine was cooling down, you'll have to do it now.

Apply anti-seize to the threads of the new spark plug. Apply dielectric grease to the ceramic part of the spark plug, to seal the plug to the wire boot.

Thread the plug into the hole tightening it as much as possible by hand. Be careful: some vehicles come with aluminum cylinder heads that can strip very easily.

Use a torque wrench to tighten to the specified torque. Torque specifications can be found using Mitchell on Demand at PartSource.

If you don't have a torque wrench, a good rule of thumb is to bring the plug up snug (finger tight) then give it between one-fourth to one-half turn more. For tapered seat plugs give it one-sixteen turn more.

REMEMBER: Over tightening the plugs can change the gap and cause other damage. Low torque may cause the plug to overheat and possibly cause pre-ignition.

Place the wire back onto the spark plug by using the left-right twisting motion. You can do this by hand (the tool is only required for taking the spark plug wire off).

Repeat the steps above for the rest of the spark plugs, making sure they're done one at a time so you don't mix up the wires.

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Part 2 of 3: Distributor Cap and Rotor Replacement
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BEFORE YOU BEGIN: Apply dielectric grease to contact points on the new distributor cap and rotor.

Disconnect the battery ground cable.

Remove the old distributor cap with the wires attached. Depending on the vehicle your distributor cap is either held down by screws or clips. If you're not sure refer to Mitchell on Demand at PartSource or talk to a Parts Pro.

FIGURE A - Distribution Cap

Remove one wire at a time from the old distributor cap, pulling boot end - never on the wire.

Install the wire on the new distributor cap in the same position. Do this one at a time so you don't mix up the firing order.

Not all distributor caps have terminal ends that the wires go over. On some vehicles the spark plug wire is held inside the cap by a wire retainer. When removing wires on this style of distributor cap, use a pair of pliers to compress the retaining clips inside the distributor cap before pulling the wires out.

Remove the old distributor rotor; it should come off real easy. If not, use a twisting pulling motion until it comes free. Do not pry the rotor off with a screwdriver; you might break the distributor.

Install the new distributor rotor by lining up the notch in the distributor shaft with the notch in the rotor.

Apply anti-seize to the distributor hold down screws.

Install the new distributor cap with wires in the same position as the old one.

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Part 3 of 3: Spark Plug Wire Replacement
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BEFORE YOU BEGIN: Check the new wires to see if they come with dielectric grease applied. If not you'll need that dielectric grease again to apply to the spark plug terminal.

Disconnect the battery ground cable.

Remove one wire at a time so you know which one goes where. Pull on the boot end, not on the wire, using a left-right twisting motion to free the wire from the spark plug.

FIGURE B - Coil Wire

Match the old wire to the new wire. The wires come in different lengths so make sure you match up the right length.

Before you install the wire on the spark plug terminal make sure to apply some dielectric grease to the wire (if it didn't come pre-applied inside the spark plug wire boot).

Apply dielectric grease to the distributor cap contacts. Depending on your vehicle apply to the distributor cap terminals or the wire retainers inside the cap.

Attach the new plug wire to the spark plug using a twisting motion on the boot until it's seated on the spark plug.

Repeat the steps above for the remaining plug wires.

Spark Plug wire boot puller
Spark Plug Socket (5/8 or 13/16)
3/8 drive Ratchet
3/8 drive Extension
3/8 u-joint adaptor
Spark Plug Gapper
Battery wrench
Screwdriver (flat & Phillips)
Pliers
Torque Wrench (Using this tool is the best way to ensure the plugs are tightened properly.)
Dielectric grease
Anti-seize compound