Learning to Tune

Good title, isn't it.

So, the most important thing to do to get started tuning is to learn to use the EFILive® Scan Tool. Tuning is about getting things right, and that requires knowing what's wrong.

The scan tool is the easiest way to pinpoint the location of the problems in the tune. Driving around will let you find the problem using your senses but once you know how to duplicate the problem you'll need to figure out exactly where in the tune to make the necessary changes.

First you need to figure out what to log. If it's a timing problem and you forget to log all the PIDs that effect the timing you might not be able to find the problem. The obvious answer would be to log everything, but you can't do that because there is a limit to the number of the PIDs you can log at once.

So, once you have an EFILive®, start scanning. Scan as much as you can and look at the logs. Try to figure out how things work. The more you understand, the easier it will be to fix it when something fails.

I never tuned it, but when I first got EFILive® I was driving a 2000 Z28 and was quite surprised to find that the PCM did most of the idle control with timing, not with the Idle Air Control. In drive with the air on timing would be very advanced, 30-40 degrees. In neutral with the air off the timing would be 10-20 degrees. While going from neutral to drive the timing would instantly jump 10 to 20 degrees to keep the idle speed constant. And conversely going from Drive to idle the timing would drop a similar amount.

Now, that's just an example, but since the manufacturer won't tell us how the ECM works we have to learn by watching the results and guessing why they happen.