NefMoto

So.. logging lambda i find these dips down to approx lambda 0.8 right after i release the trottle and decelerate.. for a brief moment.. and every time i let go of the thottle this happens.
im assuming this is the "wall-wetting" function, correct?

since im running alcohol i doubt this function would be of any use to me, other then wasting precious fuel, and so i want to disable it, how do i do this?

looking in funktionsrahmen i find maps FWFN and WFRL to be the ones to alterd.. now my WFRL map looks very strange with the definition im using, and so, i do not know what the conversion should be, or how to alter it..

..any input? someone alterd this function?  :)

If u want to disable it, just put WFRL map 0 throughout.

Is it requesting .8 or is it just actual that dips down to .8?

i dont know if i have the right definition of this map.. i think i have the location tho.. can someone specify the specifics of the map? (8/16bit, conversion etc)

im also not sure if zeroing it out will disable it completely, since it seems to ADD FWFN * nmot_w to the equation..
thoughts?



both requested and actual dips to .8

WFRL (%):

16bit LoHi 31*1 (onedimensional)
Offset: 0.09375
Precision: 3

X-Axis:
8bit Decimal
Offset: 6
precision: 4

thanks professor, that matched my definition.. =)
so.. i must have the wrong adress.. you have a picture of how the map is supposed to look like in 2d?

What ecu is it perhaps to find it for you.

06A906032HN

the attached bin..

WFRL loc @ 1559A.

awesome professor, now i can dig further into disabling this.. thank you ;D

More than welcome dear sn00k  :)

I have an 2.7bit Audi engine equiped with LPG gaseous fuel system. Engine jerks a brief moment during liftoff and switching gears is very unpleasant. I nulled WFRL in hope that it will be OK during warmup phase while engine still runs on gasoline and perfect on LPG. In first seconds I noticed that it will not be possible to use this approach on particular engine while it runs on gasoline - there is no issue on liftoff but pressing accelerator is accompanied with very noticeable judder, lag and a bang under the bonnet. Is there a way to disable wall wetting calculation on liftoff and still it be active on acceleration? What values should I target in KFAVAK?

Misguided thread.

This function is to account for the wall-film or lack thereof in order to always maintain target lambda.

It does not adjust target lambda nor is it intended to enrich on decel.

I'm not going to enrich it. I presume that jerk is because there is no gasoline film in LPG mode yet ECU is still accounting for ir to contribute some fuel. This brings lambda so high that LPG is not igniteable and I get lean missfire. Another noticed effect on LPG is that right after medium acceleration and lifting accelerator to steady speed position initialy yields lower power than needed for steady state - lambda high but no lean missfire.

prj in another thread stated that wall-wetting compensation should be disabled alltogether on gaseous fuels. As I'm on dual fuel, I want some sacrifices - compensation on acceleration for safe petrol operation during warmup and disabled on deceleration.

Wasn't really directed at you.

Look at KFBAKL and KFVAKL

Sorry to potentially de-rail the thread but I have KFVAKL map defined, I'm unsure what the numbers in the table are, are they lambda values? if not what are they?

Correction factor for fuel mass offset during decel

Ah, so a higher number within the table will mean more fuel is injected?

Not in the case of KFVAKL, the value it corrects is negative.

thanks phila!

Hi,

Any reply on this ?

I have recently same issue on mine, I've buy new lambda (280000km might be an explanation).

While cold, the engine is running fine, but when lambda operate, some uncomfortable jerk comes...

I'm running under E85, and the wall weeting is a nightmare, considering gasoline (much more present with alcool).