In Ron's posting a short while ago "An average modification PDF" I noticed something important, that I've been doing wrong. And, I've received the same info from other sources too.
Iv'e been doing the ECU re-conditioning drive, and advising others, the wrong way. What I mean is, during each of the speed steps, 25, 35, 45, etc., I've been doing smooth easy gentle accelerations up to the desired speeds. I've only done the WOT, on the freeway, as the final step. But-it's during WOT operation, that the computer adjusts the ignition timing, possibly other functions too.
So if WOT is when the ECU does important adjustments, then we ought to use WOT in all possible speed steps, within reason.
More- if a vehicle gets great results when the Groove is done, but backslides later, like a few hundred miles or weeks later-- this can be caused by constant steady consistent operation. The ECU's of today watch what's going on for dozens of drive cycles, to make some adjustments. Remember for a drive cycle to be "counted" the engine temp must get warm enough, something like over 135 Deg. F, or thereabouts. So, if a car is a daily driver, and the driver, say, drives the same trip to work and back. And, if the trip is short, or the temp doesn't get high enough, the trip doesn't "count", the ECU doesn't consider it a valid Drive Cycle.
AND- the reverse can happen too. If the fuel economy stays locked like it was pre-Groove, it may be due to not enough valid Drive Cycles having accumulated. This can explain why some vehicles need weeks of driving to finally "give in".
Ron had a Customer's vehicle do this very thing in the past few days. After weeks of little improvement to economy, it suddenly radically improved.
I've also learned, that when an ECU sees constant steady "mundane" drive cycles, it's like it thinks, "OK, I know what's going on here, now I'm gonna do what I Want!" So, if economy backslides a new re-learn might help,. Mixing up driving styles some, might keep the ECU "confused", to where it "allows" the desired improvements. Like, using some brief aggressive acceleration, like an onramp, or where possible, to vary the operation style, to keep the ECU "trying to figure things out".
Tracy G
