Can I just check what you modified your KRKTE value to?

I presume your calculation went something like this:

For gasoline
KRKTE = (50.2624 x Vhcyl)/Qstat

where 50.2624 approximately equals 1.23/(1.05 x 14.7 x 1.67E-5) where

1.293 g/dm3 = air density at 0°C and 1013 mbar)
1.05 = injector correction factor for gasoline (i.e ratio of gasoline density 0.7135 g/cm3 to n-heptane density 0.6795 g/cm3)
14.7 = Stoichiometric air quantity at lambda = 1.0 and
1.67E-5 conversion factor minutes to milliseconds.

I get 50.1621 instead of the 50.2624 quoted in the funktionsrahmen, a difference of 0.2%.

For E85 (85% ethanol)
KRKTE = (67.7104 x Vhcyl)/Qstat

where 67.7104 approximately equals 1.23/(1.1626 x 9.855 x 1.67E-5) where

1.293 g/dm3 = air density at 0°C and 1013 mbar)
1.1626 = injector correction factor for ethanol (i.e ratio of E85 density 0.79 g/cm3 to n-heptane density 0.6795 g/cm3)
9.855 = Stoichiometric air quantity at lambda = 1.0 and
1.67E-5 conversion factor minutes to milliseconds.
with the 0.2% corretion applied

So I make that an overall change of +34.7%.

TTQS

O.k. Please would you post up the calculation you did with details of old and new injector Qstat values and idle fuel trim corrector factor, etc. Apparently the level of ethanol content can vary according to time of year. Just another possible factor to consider...

I am probably misunderstanding your hardware configuration again, but if you don't have any lambda sensors, how does the ECU calculate the required fuel trim?

Thanks.

TTQS

Hi master_j.

Sorry. Yet again, I misread your earlier post.

I had a look at phila_dot's thread that you linked to. I was already working on a translation of the large module LRS 15.40 (Continuous Lambda Regulation) to better understand the basics of lambda control. However, I have started work on LRSHK 9.80 (Continuous Post-Catalyst Lambda Regulation) so we can get a handle on how the post-cat control affects pre-cat control. The following statement early on in the module is of concern:

"Regulation with the post-catalyst probe is superimposed on the pre-cat lambda control."

Hopefully this will shed some more light on continuous lambda control which should be basic knowledge for us.

TTQS