Quote Originally Posted by dfe1 View Post
When DFCO comes in on pulse width typically drops to somewhere between .200 ms and .350 ms (depending on the vehicle) and O2 voltage goes to .004 mv. With the stock cals I've looked at, the transition to DFCO is very slow because of a slow rate of spark adjustment. DFCO won't become active until ignition timing hits the value in B3336. (The description is not correct. This isn't the value to which timing will be adjusted when DFCO is active-- it's the value that activates DFCO. Spark will drop until it reaches the value in B5915.

Make sure that the value in B5919 isn't higher than the values in B3336 or you'll never hit the timing enabler for DFCO. Try values between .06 and .09 in B3334 to achieve a ramp in rate you're happy with. Values in B3335 (Ramp Out Rate) will be in the .4 to .7 range. Don't forget to adjust the other enablers (rpm, MAP, speed and throttle). If all else fails, send me your tun file.
dfe1,

I understand this is old, but if the descriptions of B3336 is incorrect, and we have data that proves that, why is it that the descriptions are never updated? I understand this is a daunting task to accomplish, but how does it ever get done? I am used to Ford tuning with BE and the biggest complaint I have about all of it, it is the lack of descriptions and clear documented logic diagrams of how calculations are actually made. I would think the entire community as a whole would benefit if there was a clear path. In the Ford market there is nothing. No clear route and if you want to search for it the task is nearly unachievable for a hobbyist.

The GM platform from the birds eye view is much better documented and defined, but I always question if this description is incorrect, what else is incorrect. I suppose that is the cornerstone of the argument to go standalone. Everything is known.

Philip