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Incorrect calculation of injector duty cycle in batch mode

Posted: Tue Dec 05, 2023 5:51 am
by GPgarage
Hello, it is a pleasure for me to introduce myself, I am Gianluca from GP garage mechatronic, I have started playing with a rusefi pre-assembled board, but I have noticed 'maybe' a problem with the calculation of the injector duty cycle in batch mode.
The FW version I'm using is: v20230525@54879, with this version I noticed that the calculation of the work cycle in this mode is twice as much as it should be, I attach a screen of the parameters and the basic calculation done on any site.
Thank you to anyone who can help me.
Best regards Gianluca.

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Tue Dec 05, 2023 5:16 pm
by AndreyB
Welcome!

First thing first you definitely should update at least to latest release https://github.com/rusefi/rusefi/releases/tag/release_20231007 :)

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Tue Dec 05, 2023 10:53 pm
by GPgarage
Hi Andrey, thank you very much for your reply, how is the FW update done? I'm no expert in this. 😅
Thanks in advance.

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Wed Dec 06, 2023 10:54 am
by mi-hol
Hi Gianluca,

there is an extensive Wiki, likely answering most of your questions.

https://wiki.rusefi.com/HOWTO-Search-on-rusEFI-wiki/

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Wed Dec 06, 2023 8:28 pm
by GPgarage
Thanks everyone for the replies,
I updated and now I get this error, I tried to find the "led:comms status" but unfortunately without success.

Thanks a lot to everyone.

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Wed Dec 06, 2023 8:33 pm
by AndreyB
for this error you would have to talk to whoever has made this board :(

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Wed Dec 06, 2023 9:51 pm
by GPgarage
with the old firmware version I didn't have this problem, didn't this mean anything?
thanks for the reply 🙂

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Fri Dec 08, 2023 6:44 pm
by GPgarage
Update:
After updating and reconfiguring the pins for the new FW I was able to carry out the test and unfortunately the outcome was negative!!!
That is, the duty cycle value is always double.
Is it possible to do anything else?
Best regards
Gianluca

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Fri Dec 08, 2023 6:54 pm
by AndreyB
Does online calculator show different numbers for individual and batch? Does rusefi show same numbers for individual and batch? Which seems right considering half of injectors being used?

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Fri Dec 08, 2023 6:59 pm
by NormanAlphaspeed
GPgarage wrote: ↑
Tue Dec 05, 2023 5:51 am
Hello, it is a pleasure for me to introduce myself, I am Gianluca from GP garage mechatronic, I have started playing with a rusefi pre-assembled board, but I have noticed 'maybe' a problem with the calculation of the injector duty cycle in batch mode.
The FW version I'm using is: v20230525@54879, with this version I noticed that the calculation of the work cycle in this mode is twice as much as it should be, I attach a screen of the parameters and the basic calculation done on any site.
Thank you to anyone who can help me.
Best regards Gianluca.
Hi

You're using an internet calculator to figure out your duty cycle, does this internet calculator know you are firing semi-sequentially? because I bet it doesn't.

From what I can see, that calculator is assuming you're firing the injectors once per cycle, in which case you'd get 1.43% duty. Since you're firing them twice (running batch/semisequential), you're getting two shots of 1.69ms, so 3.38ms of total fuel.

Why are you running semi-sequential? You can run untimed sequential without much issue (no need for cam position)

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Fri Dec 08, 2023 7:28 pm
by GPgarage
Hi, I agree in part, because if you consider two shots per lap and add them obviously the calculation is correct but other control units such as mega squirt ms2 reason as I expect, that is, it only considers the injection time for that phase and not the double.
I can attach the log if you want.
The choice is to not have a cam sensor and not to modify the original wiring of the car which is original in semi-sequential, but from what I read from your command it can also be done without it!
I don't understand how this can be possible, you would be really kind if you explained it to me.
And thanks already for the timely response.

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Fri Dec 08, 2023 8:41 pm
by NormanAlphaspeed
GPgarage wrote: ↑
Fri Dec 08, 2023 7:28 pm
Hi, I agree in part, because if you consider two shots per lap and add them obviously the calculation is correct but other control units such as mega squirt ms2 reason as I expect, that is, it only considers the injection time for that phase and not the double.
I can attach the log if you want.
The choice is to not have a cam sensor and not to modify the original wiring of the car which is original in semi-sequential, but from what I read from your command it can also be done without it!
I don't understand how this can be possible, you would be really kind if you explained it to me.
And thanks already for the timely response.
This is possible in port injection engines since injection angle is not CRITICAL, just nice to have (and does help a bit sometimes). The ECU, without cam sync, will fire or at the angle specified in Injector Phase Angle, or 360 degrees apart from that (since ECU does not know phase). You can do this with injection since the fuel will just sit there until the valve opens and it goes into the chamber (which is why you can't do it in direct injection)

Odd that in megasquirt it would show half, since we care about duty cycle in a 4-stroke event, and showing it for current 360 rotation would mean it would get capped at 50%. Anyways this is not a megasquirt or related to it so yeah that's how it works here.

Re: Incorrect calculation of injector duty cycle in batch mode

Posted: Fri Dec 08, 2023 9:44 pm
by GPgarage
Clear, Now I'll try to do my best, I'll keep you updated on how it evolves.
thanks for your interest.