Originally Posted by Vic
I have just had my MAF replaced because of a lean AFR even though it checked out ok on the diagnostic in regard to voltage levels. On the dyno the AFR would not lean out when wide open throttle was given, instead the AFR would climb up above 15.
the higher the number in relation to air/fuel ratio, the leaner it is....
15 at WOT, would be dangerously lean and cause detonation on a efi windsor..
i have mapped the afr's on my au2 xr8 ute, and found them to be leaner on slight throttle, and then seriously rich on wot, just the way the factory sets the ecu's for safety..
optimum would be around 12.5:1 afr, the factory setting is 11:1...or so ive seen with mine and a few others..