PL/TurboTweak BLM cells question

[John Larkin]

When I was on the data page, I had the car idling. Most of the 16 cells were 128 except for a few on the 3rd row. The top left cell (Cell 0) was highlighted yellow and it was locked on 137. My WB was showing idle AFR around 13.5. I got my instructions out and went into programming mode and changed that cell to 128. It stayed yellow. But the idle AFR came down to 14.7, perfect. It has been a LONG time since I dug into the whys but @ 137 BLM, the computer is adding fuel even though the wideband was showing slightly rich. Once I changed it to 128 manually, the AFR became what I would say is correct for idle. Cell 0 is low MAF and 0-800 rpm; my car idles @ 950 but whatever.

So the question is, why would the car want a rich idle? It idles in open loop like Eric designed it but I see no reason for it to be so rich, not like there is going to be knock retard at idle.

Any thoughts or opinions appreciated.

 

[SCOOBY DOO]

To my knowledge of 6.1 the NB handles everything up to 70 percent throttle. My guess would be the NB MIGHT be going south. Eric checks in once a day here...shoot him a PM. I have a basic understanding of 6.1 but didn't use it cuz I ran race gas and it eats sensors alive.

 

[Nigel]

Going a little rich on idle can help stabilize it and cover over small problems like small vacuum leaks, tip in issues, other stuff I can't think of. But if your car is in good working order, no reason to not target 14.7:1.

 

[John Larkin]

After I made the AF stoich, it was really snappy to rev, no stumble. I thought about it and it must turn yellow when it exceeds some programmed deviation from 128. Who knows, I will take a look next time I hook it up. Thanks for the replies!