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Frankenso going limp at 6,000 RPM.

Posted: Sun Oct 17, 2021 10:23 pm
by paragj
Hi all,

I have a Frankenso ECU that I'm using in a Hardware-in-Loop rig. I am using a custom 58/2 trigger signal. Things work beautifully until I hit 6,000 RPM on the crank signal. At exactly 6,000 RPM though, the ECU shuts ignitions and injections down and goes limp. I don't remember it behaving this way in the past. Here's my latest tune:

https://rusefi.com/online/view.php?msq=682

I've set both the "Cut fuel on RPM limit" and "Cut spark on RPM limit" via the limits and fallbacks menu to "No". I can't find any other setting that is relevant. I did come across this old post from a few years ago, but I'm already using individual coils and sequential injection. And I'm guessing that this issue has been fixed already.

https://rusefi.com/forum/viewtopic.php?f=18&t=1629&p=34791&hilit=RPM#p34791

Any ideas? I can artificially limit the revs that my engine models are putting out to 5,500 or so, which would in turn cause my generated crank signal to be under the limit, but I'm hoping I don't have to.

A different and not-so-important question: the LCD is too bright, and can be read only from an angle. I'm using the hd44780 setting on it. Is there a setting that I can change to make it readable? I can post a picture tomorrow if needed.

Regards,
Parag

Re: Frankenso going limp at 6,000 RPM.

Posted: Sun Oct 17, 2021 10:24 pm
by AndreyB
A log file would help

Maybe your injector duty cycle reaches 100%? That would be visible in the logs.

Re: Frankenso going limp at 6,000 RPM.

Posted: Sun Oct 17, 2021 10:27 pm
by mck1117
paragj wrote:
Sun Oct 17, 2021 10:23 pm
A different and not-so-important question: the LCD is too bright, and can be read only from an angle. I'm using the hd44780 setting on it. Is there a setting that I can change to make it readable? I can post a picture tomorrow if needed.
There should be a tiny potentiometer you can adjust with a small screwdriver on the frankenso near the LCD. It adjusts the LCD's contrast.

Re: Frankenso going limp at 6,000 RPM.

Posted: Sun Oct 17, 2021 10:39 pm
by paragj
AndreyB wrote:
Sun Oct 17, 2021 10:24 pm
A log file would help

Maybe your injector duty cycle reaches 100%? That would be visible in the logs.
Thanks, @AndreyB! I can try and get a TunerStudio log file tomorrow.

Re: Frankenso going limp at 6,000 RPM.

Posted: Sun Oct 17, 2021 10:40 pm
by paragj
mck1117 wrote:
Sun Oct 17, 2021 10:27 pm
paragj wrote:
Sun Oct 17, 2021 10:23 pm
A different and not-so-important question: the LCD is too bright, and can be read only from an angle. I'm using the hd44780 setting on it. Is there a setting that I can change to make it readable? I can post a picture tomorrow if needed.
There should be a tiny potentiometer you can adjust with a small screwdriver on the frankenso near the LCD. It adjusts the LCD's contrast.
Thanks, @mck1117! Will try that out.

Re: Frankenso going limp at 6,000 RPM.

Posted: Sun Oct 17, 2021 10:56 pm
by paragj
paragj wrote:
Sun Oct 17, 2021 10:39 pm
AndreyB wrote:
Sun Oct 17, 2021 10:24 pm
A log file would help

Maybe your injector duty cycle reaches 100%? That would be visible in the logs.
Thanks, @AndreyB! I can try and get a TunerStudio log file tomorrow.
Also, since this isn't a real vehicle, if there are values for injection-related settings that come to mind like injector flow (not necessarily practical) that I can use to side-step this issue, please let me know.

Re: Frankenso going limp at 6,000 RPM.

Posted: Sun Oct 17, 2021 10:57 pm
by mck1117
Really really big injectors will make it harder to hit a duty cycle limit.

Re: Frankenso going limp at 6,000 RPM.

Posted: Mon Oct 18, 2021 1:00 pm
by paragj
paragj wrote:
Sun Oct 17, 2021 10:39 pm
AndreyB wrote:
Sun Oct 17, 2021 10:24 pm
A log file would help

Maybe your injector duty cycle reaches 100%? That would be visible in the logs.
Thanks, @AndreyB! I can try and get a TunerStudio log file tomorrow.
I ran a quick test with logging enabled in TunerStudio. My test consists of step increases in the engine rpm by 500 every 10 seconds. Here's a quick summary of what I'm observing:

< 3000 rpm: ignitions ON, injections ON
At 3000 rpm: ignitions ON, injections OFF
3000-6000 rpm: ignitions ON, injections OFF
> 6000 rpm: ignitions OFF, injections OFF

Here's my latest tune:
https://rusefi.com/online/view.php?msq=684

I can't attach the log file (.mlg) that TunerStudio generated here. Is there another way I can upload it? Rename and upload?

Regards,
Parag

Re: Frankenso going limp at 6,000 RPM.

Posted: Mon Oct 18, 2021 1:05 pm
by paragj
paragj wrote:
Sun Oct 17, 2021 10:40 pm
mck1117 wrote:
Sun Oct 17, 2021 10:27 pm
paragj wrote:
Sun Oct 17, 2021 10:23 pm
A different and not-so-important question: the LCD is too bright, and can be read only from an angle. I'm using the hd44780 setting on it. Is there a setting that I can change to make it readable? I can post a picture tomorrow if needed.
There should be a tiny potentiometer you can adjust with a small screwdriver on the frankenso near the LCD. It adjusts the LCD's contrast.
Thanks, @mck1117! Will try that out.
My particular model does not seem to have the potentiometer near the LCD.
LCD.jpg
LCD.jpg (3.72 MiB) Viewed 4573 times

Re: Frankenso going limp at 6,000 RPM.

Posted: Fri Oct 22, 2021 12:00 am
by mck1117
It's this tiny thing on the back of the board:
image.png
image.png (8.2 MiB) Viewed 4543 times