How To Set Base Ignition Timing

Timing is one of those words that can cause quite a bit of confusion when it comes to engines and what they do. Many people mix up ignition timing, valve train timing and base timing all the time. So if you are wondering how to set base ignition timing in your car, this DIY article is for you.

Base timing refers to the engine’s ignition system and the timing of the spark igniting the mixture in your combustion chamber. This timing must be at the right time to ensure proper performance and reliability. Too early or too late of an adjustment can cause havoc and possibly destroy your motor.

Adjusting your vehicle’s base timing is easy and can be accomplished with just a set of hand tools depending on what type of engine you own. This guide assumes you know what kind of ignition system you have, whether it be distributor or distributorless and know how to adjust it up or down to set timing. Check our FAQ section for more information on how to advance or retard ignition timing in a distributor as well as distributorless engine control.

You will need a timing light or timing gun to complete this How To, and it’s always a good idea to operate safely and without any loose items or clothing.

To begin connect your timing light to your battery.

Now locate cylinder #1 on your engine and connect the magnetic pickup, our test engine is a 5.7 liter LS1. Take care when installing this wire, make sure it is clear of any exhaust piping and drive belts.

Start your engine and your timing light should begin to flash, if it doesn’t check your pickup and either change locations or check the condition of your magnets. If your timing light is able to output real time data such as RPM reference this against what you see in your instrument cluster.

Take extreme caution and point the timing light at your harmonic balancer. The flash of light your timing gun is emitting matches the point at which the spark plug is firing on the timing index. The gun is reading the spark signal and flashing the light at the correct moment.

There should be markings on your crank pulley that coincide with markings on your front engine cover.

If you can manually turn the throttle blade to rev your engine, or have a friend depress the accelerator to rev your engine for you. Make sure your vehicle is not in gear or in the PARK position if you own an automatic. Always take extreme care around the drive pulleys and serpentine belts, and use common sense.

You should see the timing light flash faster to match the increase in engine speed, this allows you to make sure the timing light is working correctly.

If you own a scan tool or a datalogger, connect this now to match the base ignition timing that your ECU sees. If you own a standalone open your program’s base ignition setting to confirm what your engine is really set at.

Understand this is a huge change you are making across your RPM range when you adjust base timing. This can be used for good and evil so do your research if you are intending to advance ignition or retard it.

Adjust your distributor or crank shaft position sensor accordingly to set timing, make sure to torque your bolts to specification and you are done! You now know how to set base ignition timing in your car. Have a comment or any questions? Leave them below.