Si Getting Knock and Misfires (Datalog attached)

[RehabJP]

I did tune my 2020 Si but I was getting the misfires before the tune when it was still bone stock. I will attach KTuner data log if anybody is so inclined to take a look at it and tell me what they think. Its not any specific tune just something I kinda made just using the check boxes since I am not sure when I load a base tune off KTuner it does not seem to load it into the software.

I bought the Pherables Stage 1.5 Tune Hopefully that will work.

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[RehabJP]

Well I guess you cannot upload .KDLG extensions on here so if anyone wants to check out the data log Ill send it.

 

[RehabJP]

 

[gtman]

Well I guess you cannot upload .KDLG extensions on here so if anyone wants to check out the data log Ill send it.

Put that .kdlg in a zip file and you can attach it here.

 

[RehabJP]

Put that .kdlg in a zip file and you can attach it here.

Hey cool thanks

 

[RehabJP]

Here is the KDLG file. I did just flash this tune this was the first drive after flashing the tune so I guess that will be a consideration. I am not so much concerned with the knock as I am with the MIsfires but not sure if this is a just like a 10th Gen 1.5T thing since as I stated before it was showing misfires bone stock the day I drove it off the lot and threw it on a scanner before changing anything.

 

[gtman]

Give me about 15 minutes to read it and I'll post back.

 

[RehabJP]

Give me about 15 minutes to read it and I'll post back.

Thank you

 

[gtman]

First of all on the "misfires", knock counts and knock control here's some great info courtesy of Derek Robinson (top 10th gen tuner)...

https://www.civicx.com/forum/threads/what-is-knock-count-and-knock-control-defined.38412/

Basically the misfires and knock counts are mostly showing noise and can be triggered by almost anything it seems; even just starting the car up. If you show 30 "knocks" on a 20 minute drive I wouldn't worry much. 100 in 10 seconds would indicate something abnormal.

On to the datalog, things mostly look good. Knock Control will always start at .59 with a new tune and drop with some amount of sedate driving. You actually drove fairly hard for most of the drive so it never really dropped much. It stayed fairly stable though so things were fine on that end.

You were hitting your boost targets. IATs were great. Fuel trims were mostly fine but were off from time to time. There were a few instances where short term went well over + or - 25%. Like in the screen below. This is where I'm not 100% sure on things. When I run my own datalogs, I'll have the odd second or so blip of maybe + or - 10 STFT but it never approaches 30 or 40%.

Hopefully one of the pros can chime in as to whether or not short blips of fuel trims being that "off" (25-40%) is normal.

 

[RehabJP]

First of all on the "misfires", knock counts and knock control here's some great info courtesy of Derek Robinson (top 10th gen tuner)...

https://www.civicx.com/forum/threads/what-is-knock-count-and-knock-control-defined.38412/

Basically the misfires and knock counts are mostly showing noise and can be triggered by almost anything it seems; even just starting the car up. If you show 30 "knocks" on a 20 minute drive I wouldn't worry much. 100 in 10 seconds would indicate something abnormal.

On to the datalog, things mostly look good. Knock Control will always start at .59 with a new tune and drop with some amount of sedate driving. You actually drove fairly hard for most of the drive so it never really dropped much. It stayed fairly stable though so things were fine on that end.

You were hitting your boost targets. IATs were great. Fuel trims were mostly fine but were off from time to time. There were a few instances where short term went well over + or - 25%. Like in the screen below. This is where I'm not 100% sure on things. When I run my own datalogs, I'll have the odd second or so blip of maybe + or - 10 STFT but it never approaches 30 or 40%.

Hopefully one of the pros can chime in as to whether or not short blips of fuel trims being that "off" (25-40%) is normal.

Hey thank you for taking a look at that for me. Yea I hopped on the highway pretty early on in the drive and got on it a bit not much street driving. I think it was a fairly aggressive tune too I notched the Boost Targets and Throttle responsiveness up to level I, killed rev hang and turned on fast spool up.

It seemed to drive okay but maybe I will just take it back to a base starter tune for now. I took it for another spin and i have STFT and LTFT on my display on the KTuner and they stayed within 2% +/- from what I saw and LTFT was pretty stable close to 0. I did buy the Pherables Stage 1.5 Tune so Ill give that a shot when I get it and keep and eye on the fuel trims. Been working on cars for years but this is my first go at performance tuning.

Again much obliged.

 

[RehabJP]

Got a lot more driving time in today and everything seems okay. Knock control went up to like .70 and then came down to .60 now with higher octane gas about .56-.59 and LTFT is pulling fuel at like -5% to -7% and I did notice some high spikes and then it dawned on me I am running the BOV plate so when that vents its causing a rich condition if only for a second since metered air gets blown out and never makes it to the intake. Not sure how big an issue this is seeing as it only vents really off throttle. I hope they get a true blow off valve for the 1.5T out on the market where you can adjust how much gets recirculated and vents so you get the cool sound and still put most of the air back into the intake. No CEL so I am gonna say its okay. Drives like a champ and the faster turbo spool and quicker throttle response does make a difference.

 

[DmK]

To be frankly with you Knock .60 is not good. Mine is always at .49 and occasionally can jump .52 with 93 octane.
About BOV it's makes a good sound, but my personal opinion that it's not good for our engines since Honda designed them to keep it curlicuing in the system. It's possibly the reason why you have fuel trim problems.

 

[RehabJP]

To be frankly with you Knock .60 is not good. Mine is always at .49 and occasionally can jump .52 with 93 octane.
About BOV it's makes a good sound, but my personal opinion that it's not good for our engines since Honda designed them to keep it curlicuing in the system. It's possibly the reason why you have fuel trim problems.

Yea I may take it off and see if things get better but its not crazy rich or lean. I know there are many schools of thought on the BOV plates and external BOVs . As far at the Knock It could still be learning its only been a day of driving with a tune I flashed this morning and it was hotter then heck here today so I guess we shall see.

 

[RehabJP]

To be frankly with you Knock .60 is not good. Mine is always at .49 and occasionally can jump .52 with 93 octane.
About BOV it's makes a good sound, but my personal opinion that it's not good for our engines since Honda designed them to keep it curlicuing in the system. It's possibly the reason why you have fuel trim problems.

Yea I did a BOV Plate delete and flashed a new tune it seems to have helped. Now my Knock Control is .49 to .50 stable and LTFT is -3% to -4% Stable. Ill have to take a look at the log and see but everything else seemed okay. The engine does seem to be more "Growley" and a bit louder at idle but I am just chalking that up to the tune as the AFR and everything else seem to be in spec.

 

[Jpierro79]

Knock is only an issue under higher load most of the time. Datalog when knock occurrs you’ll have your answer if it’s safe or unsafe. There is something called burst knock. All cars do it. It’s when you rapidly depress the pedal snapping the throttle plate open you get knock and it’s typical at 2000-4000 rpm range. It only happens momentarily and goes away. It’s a phenomenon due to the sudden rush of air vs fueling inside the combustion chamber. This type of knock is harmless. Reading knock under high pressure beyond say 8 psi should not happen often or be repetitive. This is where danger area starts. Seeing knock under full boost pressure is a problem regardless if the knock retard pulls timing as it pulls timing after the knock has occurred.
Incorrectly installing a knock sensor can cause false readings. In the case if the civic exhaust does not change knock sensitivity like some v8s do when putting headers on. We do not get increase engine harmonics from it. If you drive 30 minutes and get 10 knocks odds are it’s probably burst knock.

The factory tune on the type r even with 93 octane does it a lot. You can remove some burst knock but it’s a total pain. It’s very little return in throttle and turbo spool for a whole lot of work.

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