Si TSP Stage 1 Misfires?

[bptruett]

Hey guys, I just got a Ktuner V2 and put my TSP stage 1 back on. I was checking a few logs I did while driving around and its showing I have a lot of misfires. In these logs I go WOT a couple times just for the sake of the log and while my LTFT and knock control look completely normal these misfires are causing me some concern. Is there any way you guys could have a quick look at the 3 logs that are attached? Data log 1 looks fine but 2 and 3 are making me anxious. I also have a Mishimoto cold air intake and a muffler and resonator delete as well. Thanks!

https://drive.google.com/drive/folders/1ZepahezB-XbdlXkPbFVTv3xsZZiKNxIS?usp=sharing

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[Hollywoo0220]

W/O having to click on your link to look at your file - I would conclude that since your KCON is good you are good. The TSP tune has increased your power output and your EXHAUST modification/delete might be triggering the misfires.

 

[bptruett]

W/O having to click on your link to look at your file - I would conclude that since your KCON is good you are good. The TSP tune has increased your power output and your EXHAUST modification/delete might be triggering the misfires.

Okay thank you, I guess I just get paranoid with that, like to told my buddy if there was a real problem with misfires I would probably have the CEL

 

[Hollywoo0220]

Okay thank you, I guess I just get paranoid with that, like to told my buddy if there was a real problem with misfires I would probably have the CEL

Looking @File #3, I don't see any higher than 4 for Knock Count and you achieve just shy of <23psi and your AFR looked fine. Ambient temp was about 68-69*deg right? Not running an IC either right?
Looking @File #2, the Knock Count number was higher at about 15 and you achieved a few 10ths over 21psi, your KCON decreased to .47 very quickly just before you let off the throttle and then went back to .55 That's ok, because this data log was in much higher temps than File #3.
Looking @File #1, WAS THIS a "Lower Tune"? your PSI was much lower than #2 & #3 (about 18.4psi) and at higher RPM 5500 vs about 4600 on #2 & #3.

 

[Hollywoo0220]

Next time you data log like this; as long as the car is "driveable" - do a bit longer in the pedal down so values are better seen. I.E., just a bit more on the push is what I'm saying.

 

[gtman]

If I recall, JR from Ktuner has mentioned that if the ECU registers any "knock", the software is programmed to show that as a cylinder misfire.

Since your car is driving fine and the other parameters look OK, I wouldn't worry.

 

[bptruett]

Looking @File #3, I don't see any higher than 4 for Knock Count and you achieve just shy of <23psi and your AFR looked fine. Ambient temp was about 68-69*deg right? Not running an IC either right?
Looking @File #2, the Knock Count number was higher at about 15 and you achieved a few 10ths over 21psi, your KCON decreased to .47 very quickly just before you let off the throttle and then went back to .55 That's ok, because this data log was in much higher temps than File #3.
Looking @File #1, WAS THIS a "Lower Tune"? your PSI was much lower than #2 & #3 (about 18.4psi) and at higher RPM 5500 vs about 4600 on #2 & #3.

Yes I'm sorry I forgot to mention I was on a factory/19 tune if I remember correctly. 2 and 3 are on TSP stage 1 map 2. I'm breaking in some new tires I got put on today so once those are through I'll probably go on a dragon run and push the car hard and log it. No intercooler either and ambient was in that range

 

[360glitch]

You are ahead of many by realizing that knock count is misfire count, but rest assured that a knock count of 16 over a 12 minute drive is basically nothing. Any real misfire issue would results in knock count consistently increasing as the engine runs. You would see many hundreds if not thousands of incidents recorded over a 12 minute period and as someone else told you, the check engine light would be triggered.

 

[LBP]

There are a lot of different ways that an ECU can detect a misfire, such as monitoring the crank speed/position, data from the knock sensor, and monitoring the resistance at the ignition coils, or any combination of these. If what @gtman says is true, then consider that knock sensors are essentially highly-tuned microphones that look for specific noises from your engine and can easily falsely detect a knock/misfire here and there. This can and does happen even with a perfectly fine, stock-tuned engine in ideal conditions. I would not worry about it unless you consistently see a ton of them and other metrics corroborate that it is misfiring. What you are experiencing is completely normal and no cause for concern. Good that you are paying attention, though.

 

[bptruett]

If I recall, JR from Ktuner has mentioned that if the ECU registers any "knock", the software is programmed to show that as a cylinder misfire.

Since your car is driving fine and the other parameters look OK, I wouldn't worry.

There are a lot of different ways that an ECU can detect a misfire, such as monitoring the crank speed/position, data from the knock sensor, and monitoring the resistance at the ignition coils, or any combination of these. If what @gtman says is true, then consider that knock sensors are essentially highly-tuned microphones that look for specific noises from your engine and can easily falsely detect a knock/misfire here and there. This can and does happen even with a perfectly fine, stock-tuned engine in ideal conditions. I would not worry about it unless you consistently see a ton of them and other metrics corroborate that it is misfiring. What you are experiencing is completely normal and no cause for concern. Good that you are paying attention, though.

Thank you guys for the awesome responses! I needed the reassurance

 

[ericc191]

May I jump in here and ask a few questions?

I have a completely stock 20 Si with KTuner V2 and running TSP STG 1.

When driving, the car knock count can get up to about 60 with about 12 miles. I assume this is fine, but it only knocks around 5-10 with the KTuner stock base tune.

My second question and more concerning to me is when I am shifting during some fast driving, I can suddenly feel the engine like.. slowing or losing power (it's a hard feeling to describe) and if I look over at my KTuner's display at that exact moment, I see the K count increasing by 5 or 6 counts. This also does not happen on the KTuner base 19.5/21. Only happens with TSP STG 1.

Should I be worried?

 

[bptruett]

May I jump in here and ask a few questions?

I have a completely stock 20 Si with KTuner V2 and running TSP STG 1.

When driving, the car knock count can get up to about 60 with about 12 miles. I assume this is fine, but it only knocks around 5-10 with the KTuner stock base tune.

My second question and more concerning to me is when I am shifting during some fast driving, I can suddenly feel the engine like.. slowing or losing power (it's a hard feeling to describe) and if I look over at my KTuner's display at that exact moment, I see the K count increasing by 5 or 6 counts. This also does not happen on the KTuner base 19.5/21. Only happens with TSP STG 1.

Should I be worried?

I'm not an expert by any means but based off what we were seeing knock control is the value you want to watch not knock count. As long as your Kcon is at .49 or hovers around that by not too much you're fine

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