teminva needs to be 0.00

Reading the Me7.1 doc is like pulling teeth, even the translated one... or maybe specifically the translated one

However, as far as I can tell, TEMINVA whose usage is triggered by b_va bit, is a minimum injection time during warmup unless I am missing something. As such, the TEMINVA will be used until the engine reaches 60c and then it switches to TEMIN.

I heard comments recently (hi Nyet!) that you should see fuel cut off when decelerating but I just don't see it...

I would appreciate if somebody could post a short piece of log where it shows injectors activity or lack of thereof on decel.

I will post logs from a stock m-box and modded in a little bit, on different laptop.

So here is the summary:

TEMIN appears to be used as a wall wetting/lubricating mechanism.
TEMINVA appears to be used for the same purpose when engine is cold. Since fuel doesn't evaporate even closely as violently on cold metal vs one that has several degrees, they keep it at zero.

When decelerating, depending on b_va set (b_va - warmup - TEMINVA used), the minimum injector pulse width will adhere either to TEMIN or TEMINVA. It will never fall below these values, again depending on b_va set.

It makes it then important to scale TEMIN by your injector size factor over stock size not just low enough to stop affecting idle. I believe that too large of TEMIN will give you weird rich off or low throttle, fuel dumped in overrun which will result in AFRs dwelling in rich area for few seconds ending in overshooting into lean once lambda control overshoots and popping when resuming throttle.

How I would calculate TEMIN:
[new injector flow] / [Stock Flow] = X
TEMIN / X = New TEMIN

For example:
1000cc / 350cc = 2.85
0.50 / 2.85 = 0.175 TEMIN

TVUB should take care of all inadequacies of injector IMHO. You could use TEMIN to prevent engine stall but then you sacrifice low load drivability and some economy. Wiki already provides info on what can be done to prevent misfires etc, for some injectors you just have to raise idle RPMs/torque reserve due to their bad low pulse width performance.

TVUB is always added to final injector on time calculated for a given fuel mass needed in cylider.

So yes, TEMIN is corrected by TVUB. If your TEMIN is 0.5 and TVUB 0.8, then your final lowest injector on time will be 1.3ms.


Next time log te_w and te2_w variables, this is pre TVUB correction inside KRTI module. They are actual calculated injector on time values for perfect injector without any lag (0.00ms TVUB).

Also, ball park napkin calcs tells me that TEMIN during cutoff is still quite a bit of fuel.

I am skeptical that the injectors are still firing..