What’s Involved in a Modern Ignition Tune-up?

Posted by Jason Unrau on

Crank the engine over for two seconds, then three…then five. Finally, the engine roars to life. You drop it in gear and mash the gas pedal, but something doesn’t feel right. Your car feels sluggish, like there’s a boat anchor tied to your back bumper. The little yellow light crudely shaped like an engine is glaring at you from the dashboard. And when you come to a stop, your car threatens to stall.

For someone with a little background knowledge in cars, the first thing that comes to mind if, “It sounds like it needs a tune-up.” When a car isn’t running right, it’s often attributed to a lack of maintenance. We aren’t talking about an oil change or tire pressure adjustment, obviously, but a tune-up.

What does that mean for cars today, and how is an ignition tune-up different today than it was just a decade ago? Here’s what you need to know about a tune-up and what you need to do to complete an ignition tune-up on a car from the modern era.

What a Tune-Up Used to Be

If you looked back at the days when carbureted engine dominated the roads and belched exhaust inefficiently into the atmosphere, a tune-up had a completely different meaning. Cars might have been simpler, but a tune-up was much more involved.

  • The spark plugs would need to be changed, typically once per year.
  • Ignition cables, also known as spark plug wires, would be required every two to three years.
  • Old-school models with a points ignition system would need the distributor cap, rotor, and points replaced.
  • The carburetor would need to be adjusted, the jets cleaned, and maybe a quick rebuild while you’re at it.
  • And every few years, the car’s engine would need to come out for a complete rebuild.

Aren’t you glad that modern cars have far less maintenance? Parts might be less expensive, but overall cost was more than you’d expect because tune-ups needed to be done much more frequently.

What a Tune-Up Includes Today

Modern engines are all fuel injected today, stripping away a lot of maintenance that would’ve been needed. And overall, they’re more efficient, cleaner, and way more reliable. But there are still items you need to complete as part of a tune-up. 

For a typical engine today – be it a 4-cylinder, a 6-cylinder, or an 8-cylinder engine – tune-up items include:

  • Replacing the spark plugs. Rather than once per year because they’re fouled by oil or fuel, spark plugs are replaced because the electrode wears out. Typically, that’s every 60,000 to 100,000 miles.
  • Changing oxygen sensors. While O2 sensors may need to be replaced from time to time, they’re usually only replaced when they fail – but they are ignition related.
  • Fuel injection cleaning. No matter what grade of gas you buy or from which station, impurities in the fuel clog up the spray pattern on the injector nozzles.
  • A battery test. Yes, even the battery is included in an ignition tune-up because all systems need reliable electrical power.
  • An engine air filter. To maintain an engine’s efficiency and for proper air-fuel mixture, a clean air filter lets the engine breathe.
  • A computerized diagnostic scan. Especially important if the Check Engine Light is on, a diagnostic scan will let you know if sensors are operating as they should.

How to Perform a DIY Ignition Tune-Up

Vehicles today are highly computerized, but with a few rather common and inexpensive tools, you can do your own ignition tune-up to save money at the repair shop. The best way to know when any item is necessary is simple: follow the maintenance schedule in your owner’s manual religiously.

Change the Engine Air Filter

It seems minor and trivial, but it’s oh so important. The engine air filter should be changed once per year or every 12,000 miles approximately, or when it’s dirty.

Locate the air cleaner housing under the hood. Whether your vehicle uses a flat rectangular filter or a cone-style element, it will be fabric-like and pleated. If you can’t see through the filter when you hold it up to a light, it needs to be replaced.

Purchase only the exact replacement for your car. An ill-fitting air filter can either let dirt past, potentially damaging the engine, or restrict the airflow and force your car to burn more fuel.

Test the Battery

A weak or discharged battery can wreak havoc on sensors and modules, causing electrical gremlins that can be very hard to trace. A poorly-running engine or false engine codes can potentially be attributed to a failing battery.

Every year, test the battery health to ensure it is healthy and holding a charge. While it’s a 12-volt battery, a fully-charged car battery will have a voltage of 12.6 or higher. A simple test with a voltmeter when the engine is off can identify if the battery is weak.

The normal lifespan of a car battery is three to six years.

Clean the Fuel Injectors

Every pulse of a fuel injector mists the equivalent of a raindrop of fuel into the cylinder. That happens hundreds – or thousands – of times per minute. It’s no wonder that they get dirty with fuel contaminants over time.

An in-tank fuel injector cleaner like Liqui-Moly can help reduce build-up on fuel injector nozzles and keep deposits at bay. However, every 12 to 24 months, a comprehensive fuel injection system cleaning is beneficial to restore their condition like new. A fuel injector cleaner kit is usually run through a vacuum hose into the intake as a substitute for gasoline to clean the injectors thoroughly.

Perform a Diagnostic Scan Test

If you have a Check Engine Light or other malfunction indicators on, you should have it diagnosed right away. It can point you to a condition that affects your car’s reliability or efficiency. One example is an oxygen sensor. This component measures the gas levels in your car’s exhaust and adjusts the air-fuel mixture accordingly. A knock sensor, idle air sensor, camshaft position sensor, and several others are also crucial to engine efficiency.

When you’re performing your routine maintenance, scan your car’s control modules for fault codes. If there are any, research them and address them accordingly.

Change the Spark Plugs

Ah, something familiar for an ignition tune-up! Your car’s spark plugs need to be changed, but very infrequently unless there’s a misfire. Not only are the spark plugs built better to be longer lasting, but engines overall are built with tighter tolerances and improved operation to keep spark plugs in good shape for longer.

Still, you’ll eventually need to replace spark plugs. Most engines now have a coil-on-plug design where each spark plug has an ignition coil directly over top of it. You’ll gain access to the spark plugs when you remove the coil.

Replace spark plugs with one specified for your vehicle. They have different heat ranges, lengths, and styles so they are not interchangeable. Carefully unthread the old ones and install new ones, torqueing them to the manufacturer’s specification.

It’s not a difficult process to complete, and it’s usually required only every five years or so, or up to 100,000 miles.

While You’re At It…

During an ignition tune-up is a great time to check up on the rest of your car’s maintenance.

  • Inspect each fluid under the hood and in the drive train for condition, and change the fluid if necessary.
  • Check the cabin air filter to ensure it’s clean.
  • Change the engine oil and filter if you’re nearing your service interval.
  • And perform a thorough visual inspection to determine if anything else is loose, broken, leaking, or worn.

When you’re preparing to do an ignition tune-up for your vehicle, high-quality components will ensure that you won’t be repeating the process prematurely. At After OEM, you’ll find the right parts for the job at a competitive price.