Injection time suddenly dropping at about 3000 RPM but without effects

[Shaker]

Can anybody explain this logs to me? I don't understand what happens at the marked spot.

Injection time dropping 1.png

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Injection time dropping 2.png

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The log shows a full throttle low to high RPM run in 2nd gear of a CA18DET with a GT2560R, 350Z MAF and 444cc injectors.

After exiting the o2 closed loop area, the injection time rises until it is 9.84ms and then suddenly drops to 5.40ms even though no other parameters have changed, that might have caused this. O2 doesn't change either so I guess, the mix is not actually getting lean. With half of the injection time?

Injection time is linked to the load index very closely, but load rises fine when injection time is making this drop.

This seems very illogical to me. Please help me understand this. If needed I can send log and map.

[Matt]

ECU switches from sequential to batch mode

ECU injects both cylinders and halves the injection time once a certain injection time is reached

[Shaker]

Oh, that's interesting. I didn't know that.
I guess it injects 1+4 then 2+3, then 1+4 and so on and the "unused" fuel sits there and "waits" until the second injection comes and the intake vale opens.

Thank you!