AFR Tuning with Megatune
Posted: Tue Aug 23, 2011 8:12 pm
When live tuning my AFR table I'm a little confused. I'm using Megatune 2.25 and the O2 sensor is an LC1. The red X is the spot in the table being tuned, and the moving green dot is where the engine is curently in the table. Directly below the table is a line of red data that appears to indicate the rpm, load, and the AFR corresponding to where the red X is in the table. There is a line of green data indicating the current rpm, load value, and AFR of the running engine. As I tune a cell, the AFR value in green reacts as I would expect it too, and based on how the engine runs I think it's probably correct. My confusion comes from the value displayed by the large AFR gauge on the left side of the screen. It responds to my tuning changes, but is very erratic. It also shows an AFR 2 -2.5 points less than the value in green. If I tune to an AFR of say 14.5 using the green value, the AFR gauge will read somewhere around 12 - 12.2. If I lean to the point of what appears to be lean misfire, the AFR gauge indicates a mixture of maybe 13.1 while the data in green indicates an AFR closer to 16.1. I guess my question is, should the AFR Gauge and the AFR value in green match, and if so why don't they? A glitch in the software? Or do I ignore the values in green since I haven't found a reference to them in any of the tuning documentation I've read, even though they appear to be the correct values. All I've found references tuning the AFR using the large AFR gauge. A lot of writing for a simple question.
Thanks
Thanks