NefMoto

Hi all, ive been looking through the map for my 1.8t ajh Alhambra and was wondering if the KFFA map is the same or similar as the KFLBTS map on the later ecu's, its listed as "Fuel Injection Enrich Map f Cat Protec during High Load" it also contains some wild rich values 567,465 etc etc  I can say that its trigger point is TKATMTRP set to 400c so its looking more and more likely. thanks all.

Bump..anyone.

trigger point will be exceeded fast on a turbo'd car.

sounds like your map but have no experience on that ecu,

Which exactly is your problem? to much fuel after some EGTs? or in some Load areas?

Thanks for the reply guys, I'm trying to understand in what manner these numbers are used to calculate fuelling at high load, it can't be lambda afr surely as some of the numbers are so low that I'd be spitting fuel out the back. Are these values injector on time perhaps.

think of it as fkkvs.

KFFA – Kennfeld für Anfettung zum Kat-Schutz bei ständig hohem tL.
Attached is an example of a OEM M383 KFFA map. I understand it as (ms) injector time that will be added to current injector values at some LOADs and some RPMs.

(http://i63.tinypic.com/s2b9ky.jpg)

Thank you again, appreciated. I did find the other maps that direct to this one and by my understanding this map is used when load enters the 6ms area and on and at all other times the mixture is held to stoichiometric...thanks once again for the direction.

Assuming it won't be alive until calc cat / load is exceeded?

I think so.

Bit more like bts then.

Exactly right, the trigger map is 400c so very much the same as me7 etc. Just harder to calculate as it doesn't use afr but what looks like some amount of addition.

How do you know is 400C? what trigger map indicate that to you?

Kat-Modelltemperaturschwelle für Erkennung Ersatztrip (TKATMTRP) set to 400c

I've seen this type of strategy b4 on me7 on wideband cars from factory.   This doest make too much sense without seeing the rest.

Just out of interest, would this wideband me7 happen to be an early revision of the me7 map. I can see that nearly all of the narrowband versions use an almost identical kffa but make changes to the the trims map according to the vehicle.

It was on 04+ Volvo R's with returnless fuel system, constantly in BTS from factory.

Resurrecting this old thread.   I have similar questions about KFLF.  Running a 1.8T AEB with M5.9.2. Under stock setting I have logged the following wideband AFR and see it dips down to 11-11.5 under high load and high RPM.

 Curios about the fueling logic here:

I was thinking once load values in TLRAN (Lastschwelle Lambdaregelung) are exceeded, the injector time values in KFFA (Kennfeld für Anfettung zum Kat-Schutz bei ständig hohem tL) and perhaps KFFAVL (Kennfeld für Anfettung zum Kat-Schutz bei VL)  are added to what is specified by KFLF (Lambdakennfeld bei Teillast) values.  I believe the values in KFLF are a multiplier correction from lambda = 1.

This does not make much sense when I look at my map values.  Values in KFLF are all close to unity for my bin (1997 A4 B5 1.8T) and the KFFA and KFFAVL are all zero for the stock settings so I assume nothing is added yet I seem to drop way down below stoich when under load.

Where is the correction coming from once I go open loop?  I must be missing a map somewhere.  The alternative is that in open loop I am still only using the KFLF values and small increases in KFLF values  (slightly different values than 1) make the big changes in AFR for the load & RPM I logged.  If correct, it must be highly non linear. 

If I desire to run AFRs more close to 12.5 under open loop, do I play with values in KFLF where I exceed loads in TLRAN?  Please let me know if I am missing a map and additional logic for fueling.

Thanks for whatever info you can share.

If your closed loop fueling is fine and your open loop isn't, it means your entire fueling path is miscalibrated, and the only thing saving you is closed loop, which corrects all of your mistakes.

Maybe KFTLWS  ??? ??? ???

Was hoping you would help yet again :).   

Will have to study this map.   I have been assuming the following description meant only for limp mode correction.  Will dig in and see if I can make sense of it.

KFTLWS - Kennfeld für tL - Berechnung aus Drosselklappenwinkel, Nockenwelle spät

KFTLWS = Boost Control Engine Load Map wo MAF – Alpha N map – Limp Mode
X/Y/Z  Throttle Body Angle Degrees (°) / RPM / Load (ms/RPM)

From PRJ (Nefmoto) answer:
Limp mode Alpha/N map with MAF disconnected.