Recent Posts

1

Calibration & Mapping / Re: Individual Cylinder Power - usefull tool

« Last post by Machismo on September 28, 2023, 03:19:32 pm »

Yes they are bouncing "minimum to maximum" when engine is at idle and even when engine is off, there is still a bit some bouncing activity going on on some cylinder displays.

2

Calibration & Mapping / Re: Individual Cylinder Power - usefull tool

« Last post by z0tya on September 18, 2023, 03:47:43 pm »

I have had a log with disconnected injectors at first the 1st cyl then 2nd and so on, but i have not found it
But your log a bit wierd for me especially the before cran section, why individual power boucing and not stay at -512usec...

3

Fuel Injection / Re: Strange stuttering while driving with constant speed with a Porsche 944 Turbo

« Last post by GintsK on September 14, 2023, 09:34:45 pm »

Seems you drive on too retarded ignition for that load point. No? When engine gets degree more, it gain power and go in cycle back - forth.

Try add ignition there. Probably at that point you want 20...30deg. You can avoid steep Ignition table by retarding ignition with MAT/TPS table at low throttle openings but keep high values in RPM/MAp ign table. It helps for driveability. 

Second thing to try is to change Injection angle. In 720 cycle there is one point where something like this happens.

4

Calibration & Mapping / Re: Individual Cylinder Power - usefull tool

« Last post by Machismo on September 14, 2023, 07:09:34 pm »

Yes what I was reading that people had success with 4 and 6 cyl. So those are confirmed, I think.

Sure, I disconnected now cylinder 1 which should be channel 0. Started log, started car, let it run on idle for a moment then I revved to couple of thousand rpm:

http://vems.hu/download/VemsTune/bugreports/Report-2023.09.14-21.03.19.zip

I am wondering, if you disconnect one of your four cylinders, do you see it's then completely "out" in the power display, or is there a little bit power still shown? If you have interest and have not tested without one cyl before, try it with both idle and lets say 2500 rpm.

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Calibration & Mapping / Re: Individual Cylinder Power - usefull tool

« Last post by z0tya on September 13, 2023, 02:16:11 pm »

I have only experience with 4 cyl.
Could you upload some log?

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Calibration & Mapping / Re: Individual Cylinder Power - usefull tool

« Last post by Machismo on September 12, 2023, 05:44:35 pm »

Thanks for the swift answer.

I checked that but I had already the right selection there: "Realtime Data Option: ADC/Individ.power"

I now, just for testing put it to "Individ. knock data" which caused the individual power to stop showing anything. (like you said)

So, my problem is not that it wont show anything, the problem is, it shows mostly garbage. For example that if one cylinder does not ignite, I do not see it from the individual power display, they seem all pretty even at 2000 rpm. Only if I disconnect two cylinders, I start to see some less power in two "bars", but even then, they are the wrong cylinders.

Could it be that knock sensor would create some disturbance, should I disconnect it? I mean, if they are handled by the same circuit.

Edit: I disconnected the knock sensor, did not help, individual cylinder power readings still remain erratic.

I start to think that 8 cylinders has too many events per 60-2 trigger tooth for Vems to really see the differences between cylinders, unless of course someone can confirm that they have successfully used this feature with eight cylinders.

My 3.6 board is one of the very early ones. Could it be my hardware is not exactly the same as it should to be able to handle this?

7

Calibration & Mapping / Re: Individual Cylinder Power - usefull tool

« Last post by z0tya on September 12, 2023, 10:36:20 am »

Individual power works only when knock real time data disabled:
Vemstune Inputs/Knock Samplings/Knock real time

8

Calibration & Mapping / Re: Individual Cylinder Power - usefull tool

« Last post by Machismo on September 11, 2023, 06:47:30 pm »

I got excited about this individual power stuff, I have a V8 and when I turned the individual power gauge on it showed all 8 cylinders bouncing around at idle. Then I increased rpm to 2000 and 3000 and the display stabilized showing some cylinders a bit stronger than others. At that point I assumed it works since it looked convincing... Then I disconnected one cylinders coil which made one cylinder went dark. But it didnt change anything! All cylinders still according to the gauge were active. Why it does not work?

I then red this

https://www.vems.hu/vt/help/v3/datalog/individual_power.html

There is info about the association of the numbers, but no mention of 8 cylinders. Why the info is missing, is it supposed to work? I have a 60-2 trigger wheel, 3.6 board and latest firmware etc. So little information available about this subject, please enlighten me. I really would need this to work to be able to tune my engine better.

Oh one more thing, if I just power on Vems, some of the individual power gauges start to bounce erraticly, where does that come from? They should be at zero when the engine is not rotating.

9

Ignition / Re: Using the Stepper Motor Driver to control Ignition

« Last post by Kamuto on September 03, 2023, 11:38:21 pm »

Hi All, its been a long time since i needed to enquire on here, so excuse my ignorance, but i'm resurrecting an old VEMS SR20DET project... My standard nissan COPs are currently driven via the Stepper motor driver (and via the Stock ignitor) but they are now showing signs of failure, so my question is...
Can someone confirm if the VAG COPs (i have some NGK R8 U5014 available) can be driven by the same stepper outputs with no modifications? (with the stock ignitor removed of course).

yes

10

Ignition / Re: enabling camsync makes ignition pause in cycles

« Last post by Kamuto on September 03, 2023, 11:37:44 pm »

that's because it's not getting cam signal