EFI Anyone?

[Gaz64]

Originally Posted by Texasdoc

If you ran it already with the new afr target, you probably don't need to edit the fuel table. Look at the learn table at the idle cells - how much adjustment is it making?

Boring EFI stuff to follow. Ignore it if you like. Maybe it will help somebody in the future. Took me forever to learn how the EFI system worked.

There is a table (don't remember it's name - let's call it the limits table) that limits how much the system will adjust the learn table to reach the desired AFR. Let's say this limit table is set at 5% in the idle area. Your system will start with the fuel table, read the O2 sensor, then compare that to the AFR table. If the measured AFR is lean, it will add fuel to the learn table. If it is rich, it will subtract fuel - it can even be negative in the learn table. The system always mathematically adds the fuel table to the learn table. If the learn table hits the maximum change listed in the limits table, it won't adjust it any further.

So if your fuel table is at 5, your learn table is at 1 and your limits table is at 25%, the system will increase the learn table to 1.25 in an effort to make it richer.

So, in your case, you adjusted your desired AFR then ran it. You didn't adjust the fuel table so the system likely increased the fuel by increasing the learn table. So unless your learn table is being limited by the limits table, you are okay. Got it?

If it still hunts, play with the afr a bit. Go to 12.5 - see what happens. Try adjusting the timing in the 9 cells of the idle - 9 cell grid - 3x3. Find the one cell that your car mostly idles in. Make the cells with a lower rpm (three on the left) one degree higher than your idle timing and the three on the right 1 degree lower. Try 2 degrees on either side. The faster timing helps the motor speed back up to the desired rpm, the lower timing helps to slow it back down. Find what your motor likes.

I love reading from others that truly understand what they are talking about.

I use timing in the same manner to control idle speed on one of mine with a carb.

Gary