I am using Tuner Pro RT with the AutoProm to make adjustments to my 89 L98. I am using the stock APYN bin with the following modifications due to an intake/runner and cam change. I raised the idle to 625. I set the base timing in the chip and with the distributer to 8 degrees. In the timing table I moved the values in the 800rpm row and 64 to 80 lv8 columns from 15.47 degrees to 16.88 degrees. While monitoring the engine this appeared to give me the smoothest idle. I had to make a very small adjustment to MAF table 1 to get the idle BLM and INT at 128.
What I want to make sure I understand.
I have a good idle and I believe the sum of the two idle components gives me an overall initial timing advance of 24 to 25 degrees. Do I understand this correctly?
It appears now that the engine is a little harder to start and will overheat on idle. Is this related or a coincidence?

 

You should set the constant for the initial advance bias to be what you have it set to with est disconnected, so in your case 8 degrees.

You can set your idle spark stuff to whatever you want. I forget if $6E has a closed tps vs open tps spark advance, maybe that was just a $58 thing but double check that. I idle around 25 degrees but I have a big cam.

Tunerpro should take the bias constant and calculate that into the main spark advance table. I know TC does for sure. So what you see should be what you get. When you log, you should have two columns. a "advance" which is what the ecm adds, and "total" which is what the ecm adds + the initial bias.


-- Joe

 

My understanding is that $6E uses the same spark table for both closed and open loop. If that is what you were thinking about. The two references on the data playback are Spark advance relative to top dead center, and spark advance relative to reference pulse.

 

Yes, the stock 6E.xdf that comes with TunerPro does take the bias constant into account, so editing the main spark table is WYSIWYG.