About knock control issue

[gcapraz]

Hi everyone,

Some of my friends using ktuner and they have knock control rising problem without knock count. It rises on normal driving not full throttle. İt goes like 0.80 at the beginning and then rise through 1.20. They used 87octane and 95 high octane fuel and it didn't work at all.

İs there anyone else who has faced same problem?

For setup, they both have dp fp mst filter big intercooler and ktuner with 21 basemap.

İf anyone who has an idea, pls share with me

Thanks ?

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[kadireren]

I have a similar problem. Knock control increases at partial throttle such as %26 TPS and around 105 km/h. İt increases from 0.49 to 0.70. I think it is something related to -psi vacuum because when the TPS above %30 and map pressure above 0 it starts to decrease. ı am sure it is not because of the quality of gasoline.

 

[arnoldo]

Try to change MAF quick calibration back to "Factory MAF Calibration" or "Factory MAF Calibration w/ Scaled Top End" calibration. I experienced the same issue as you but Knock Control back to normal. Knock control stays at .49 after this change. I'm using 98 RON fuel.

 

[kadireren]

Try to change MAF quick calibration back to "Factory MAF Calibration" or "Factory MAF Calibration w/ Scaled Top End" calibration. I experienced the same issue as you but Knock Control back to normal. Knock control stays at .49 after this change. I'm using 98 RON fuel.

But if i don`t use custom maf calibration, it runs super rich and ltft increases to -8.

 

[gcapraz]

i could not find any effects with changing maf scaling. Also i could not find the solution with changing software. i dont know how its happening. Probably there is some mechanical issue effects it. Maybe spark plugs or other things.
There is no any knock count
There is no lean afr
ltrim strim stays around +5-5
We add some toluen for become high octane

It looks like knocking sensor is feeling fake knocks.

 

[arnoldo]

It happened to me. I changed MAF Quick Calibration under MAF Scaling section from "Custom" to "Factory MAF Calibration". I took the same route as I did yesterday when my knock control elevated to .6 with partial throttle, and I don't re-fill the fuel so same fuel. Calibration was the same calibration with only MAF Scaling change.

Knock control only moved a bit to .53 but then stay at .49 all the way until I stop.

My ECU has no LTFT. There was a blip of STFT reaching value higher than +10% and lower than -15% but knock control is normal.

 

[KTuner]

Unless you changed the MAF scale yourself "Custom" when you open a new tune is factory, so going to "Factory" would change nothing. Flashing reset your trims / adaptations and your environmental factors today would appear to be more favorable for your fuel and setup.

 

[arnoldo]

Unless you changed the MAF scale yourself "Custom" when you open a new tune is factory, so going to "Factory" would change nothing. Flashing reset your trims / adaptations and your environmental factors today would appear to be more favorable for your fuel and setup.

I did changed the scale to "Custom" & made adjustment to the AFM flow. I created new calibration, which basically the same calibration as yesterday, but choose "Factory MAF Calibration" In MAF Quick Calibration.

Environmental factor is the same as yesterday. Same weather, & same temperature. Typical tropical climate, we hardl have significant environmental change.

Maybe running too lean could also activate knock control.

 

[KTuner]

If you adjusted the MAF curve and putting it back fixes it consistently, your changes were likely the cause.

 

[Gruber]

It looks like knocking sensor is feeling fake knocks.

Kcont doesn't seem to be coming solely from the knock sensor. It must also be using other parameters such as temperatures, load, rpm, boost, MAF and whatever else it wishes to figure the current risk of knock, using some cormula based on the prior knowledge of the engine. This is probably not accessible.

That's because knock is random ("stochastic" is the proper term), which means it can happen anytime with DI/turbo engine as conditions change while driving, and it is not always preceded by gradually increasing knock noise. You could get that one money knock without warning.

Then if you are spiking your fuel with toluene, you could be in fact far from knock, (or not, who knows) but the ECU will still use the same knock comtrol algorithm based on the same parameters in absence of actually sensed knock noise.

In other words, at some conditions labeled as "very high risk of knock" the ECU will retard timing and trim power even in there is no knock detected, instead of just assuming you must be running some racing fuel.

 

[Ron21]

Unless you changed the MAF scale yourself "Custom" when you open a new tune is factory, so going to "Factory" would change nothing. Flashing reset your trims / adaptations and your environmental factors today would appear to be more favorable for your fuel and setup.

Unless you changed the MAF scale yourself "Custom" when you open a new tune is factory, so going to "Factory" would change nothing. Flashing reset your trims / adaptations and your environmental factors today would appear to be more favorable for your fuel and setup.

—what does Factory MAF Calibration w/ Scaled Top End do? What difference on stock factory maf setting?

 

[kytos]

—what does Factory MAF Calibration w/ Scaled Top End do? What difference on stock factory maf setting?

It leans the maf scale at high loads because it reads high from factory, useful if the ECU doesn't run at closed loop at wot and the actual AFR is richer than the target.

 

[shhadow]

Having the same issue, wondering if anyone have a solution?

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