I have been running the Data logging with the SERT on my 07 Ultra and watched as the ecm changes the VEnumbers to compensate for theAFRas read by the 02 sensors, I have read earlier on this forum about adaptive learning capabilities, my question is does the ECM actually adapt and store in memory, (change existing map) for future reference or is it merely reacting to the feedback of the 02 sensors on the fly?

 

The ecm does not learn or remember info to store for next run. There are too many vaiables. No ride will be the same-- EVER. If it remember the last ride it would have to change anyway on the next because whos to say the air was not as dense or or gas was older or you decided to really hammer it or it was very hot or it was very cold or you sat in traffic or you were on the highway or your steady throttle position was 10% off from last time or ok you get my point.

 

You could not be more incorrect. Adaptive learning means that if it continuously does something, it stores it in he ecm. Say you slipped on mufflers, the adaptive fuel would increase and the next time you ran the bike, the base map would already be increased. It also applies to open loop. You do not understand the speed density system - everything you stated is basically opposite of what happens. The VE tables indicate percentage of efficiency - the other sensors account for air temp, altitude etc.

 

So if I understand what you are saying , when I Data log again I should see that the Ve correction would be less than when the bike was first ran with this map based on the ecm adapting to mymotors actual requirements. If this is the case, the 07 ECM's are not getting the credit they deserve. Also, does the ecm adapt the timing tables or just fuel tables?

 

Wait a minute.....6 weeks agowhen I suggested that I had dyno data that indicatedthe 07 takes what it learnsin closed loop and applied it toopen loop. You ripped me a new,after accusing me of being in a drug induced comma. What changed in the last few weeks??

Your Quote
You are smoking some serious Chit and could not be more wrong. The system doesn't operate the way you think. Your results are either warm up fuel, engine temp or a different gear.
https://www.hdforums.com/m_1265353/tm.htm

 

At the risk of adding to some of the confusion, I'll try to help.

Basically everyone is saying the same thing, the '07' ECM learns thru fuel adaptive learning during part throttle closed loop and applies this learning to full throttle open loop. But, here is where the confusion may exist, the learning that is applied to full throttle open loop could be entirely wrong on a modified engine.

The original intent by the Delphi ECM is to monitor changes during closed loop and compensate forsuch as engineengine wear, atmospheric changes, minor modsetc.For example, if theclosed loop adaptive learning biases the fuel more rich, they assume that this bias should apply to open loop also, which is usuallya good assumption if stock. However, let'ssay we modify the enginewith a more radical cam. Due to the less vacuum at closed loop, part throttle operation it nowuses a more rich area of the VE map table, thinks it's under more load. Now the adaptive learning has to decrease the fuel to maintaing a 14.6:1A/F. Here's the clinker, it willtransfer the learned leaneradaptive learning to wide open throttle open loop andleaningout the A/F ratio when in fact thehigher performance cam actually requires more fuel now and wecould be dangerously lean at WOT.

So yes, everyone is right, closed loop learning is applied to open loop, but it has no wayof knowing if it is correct or not because there is no feedback during open loop, so on amodified bike, tranfering this learning can do more harm then good and should be custom tuned. On manynon Harley ECM's thatI've worked on with modified engines, if possible,we disable adaptivelearning for that reason.

 

Hi fellas, I've been reading all the posts I can find about this subject (many of them involving you guys) trying to get a handle on what is really going on with the SERT and the O2 sensors.By applying the aforementioned logic a little farther forward... does this mean that the richest AFR you can ever achieve in closed loop would be around 14.1 (that is with the CLB values maxed)? Based on what is being said, it seems it doesn'tmatter what values you provide in the front/rear VE tables (within reason), when running in closed loop the O2 sensors will detect the 'true' VE%, and correct it, eventually populating the tables with the correct value? Is that a true statement?

 

If I understand your question, no, that is not true. The closed loop fuel trimscan only correct up to a point, the CLB can offset the normal target of 14.6 A/F somewhat but again wehave correctionlimits. If theHD flashedVE table is set clear off the mark, the fuel trims and SERT programming added together may not have enough rangeto correct andwe could wind up with any incorrectA/F ratio, possibly much more rich then 14.1.

 

I have read in another post you stated youhave tuned fuel injection for two decades, my question is, how would you go about tuning the SERT on the 07 with a mildly cammed engine, say for example a camsuch as the popular andrews 37 grind, would you set all afr cells to 13.2 to set up VE's and thenreactivate them by changing the cells you wanted back to 14.6 or would it be more productive to simply tune it like the old ecm's, not using the 02 sensor feedback at all and set the afr cells to the fuel curve you want after correcting ve numbers with a sniffer? Seems to me you could get into some trouble if the ecm is adjusting on its own in the open loopportion of the map using by using feedback from the closed loop operation on a nonstock motor.

 

My dyno tuning experiance has been mainly in the high performance automotve field plus my own bikes. Even though I have tuned many Delphi ECMs with different tuning programs, I have never worked with the SERT programmersohopefully some withdirect SERT experiance will help out here.

As far as your example of afr cells to 13.2, setting VE, then afrto 14.6, are you in closed or open loop and what is your Closed Loop Bias table set at? I'm not sure how the SERT would handle that, but Iwould think that theCLBtable would override your afr cells while in closed loop. Here is where we needsome with actual SERT experianced input.

I would not disable your O2s, they are a positive EFI advancement for the HD andan asset for maintaining a good tune over the long haulwhen tuned properly.

Touching on your concern about the transfer of closed loopfuel adaptive learning to open loop, full throttle operations, using a scanner such as theTwin Scanto monitor fuel trims is important. I maybe using improper terminology for HD ECMs nowbut I believe thefuel adaptive learning is made up of short term and long term fuel trims. A good 07bikeSERT tuner will spend much time, hopefully on a load typechassis dyno to simulate actual driving conditions, tuning closed loop at many different RPM and load positions. This is done to get the long term fuel trims as close to zero as possible by tuning the VE table. Many tunersset the VEsuntilthe trims areapprox -2 to -7% negative (98% to 93% indicatedon Twin Scan)because ECMs do not transfer negative fueltrims from closed loop to open loop. Doing this willhelpprevent our WOT OL afr from drifting if the long term fuel trimschange somewhatwhile riding.Example, if the trims are positive,such as110%,and the WOT OL afr was dialed in exactly where we want it, if the trims changed to 105% or less, this would cause the WOTOL afrto go approx 5% or more leaner, possibly too dangerously lean.As indicated before, setting the VEs so the trims areslightly negative can prevent such adrift to alean condition. Ifthe tuner does not manage the CLfuel trimswhile tuning, a bike could be tuned perfect for WOT on the dyno but be way off by the time the bike getsrode home. Good tuners earn their money.