Is my engine knocking?
 

Hello guys, always getting some good answers here so I’m gonna ask away. I’m currently running nameless long tube headers with oft stg 2+ 93 octane tune. Few days ago I’ve had p0030 popped up, I believe it’s my o2 sensor. I had the CEL for days and it went away by itself.. and now I’m just diagnosing everything and I noticed that my tablet shows KC learning number which is keep going up (anywhere from 0-6.00) during acceleration and sometimes I see anywhere from 0-2.00 briefly on knock corr column during acceleration. If anyone knows any of these symptoms it would mean a lot. Thanks guys

KC learned goes up higher as you step the gas pedal deeper right?

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Yes it does and knock corr sometimes pop up as well

Same here. But without all your engine problems. So maybe it's not the cause of the engine code. Also, the code means you might have faulty o2 sensor. Hmm I'm not sure but I don't think youre knocking. Cuz when ur car knocks, you can tell it's noticable.

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Take a log with the OFT and post it in the tuning section. You will soon get the answers you seek.

Does the IAM drop after a few minutes? Also a log would be great.

I dunno but tell it to use the doorbell next time

:slap:

https://yarn.co/yarn-clip/2bd891a1-3...byhhqqmFx.copy

^^^^This. Post a log, be sure to read the sticky's in the software forum, otherwise it will likely be useless.

so when the car is started it starts from .70 and it goes up to 1.00 after few minutes of driving and yes i’ll try to upload my log.

don’t have one but i’ll see if COBB sells a aftermarket one for my fa20:lol:

IAM is driven by the knock sensor and resets after a engine shutdown/startup cycle. I normally use that as a determining factor as to whether there is significant amounts of knock currently.

KC learned I believe is persistent across engine shutdown/startup, so those values indicate regions where it has detected knock from sometime between the last time you flashed and now. This indicates that your engine is already reducing timing in that region.

So with IAM at 1, and KC Learned at some value, it shows that your engine is not currently knocking, but has knocked at some point in the past.

Ah that makes sense, I know knocking in engine can cause by improper air to fuel ratio, do you think having a faulty upstream and downstream o2 sensor can cause this problem?

Yes, it is definitely possible. The more upstream sensor is the important one for afr as I recall. The one further downstream is just a check to make sure the cat is working , which I think you don't have. Running lean is likely to induce knock.

Any idea what your ltft is? It changes at different load values (load increases with airflow) so you might need a log to see it. Basically if your o2 sensor is messed up, you are likely to see large + or - values in your fuel trim.

I’ll upload a log by tonight here and tuning thread as well. I’ll have to look at those values I know my ltft value kinda goes everywhere(-8.00~+5.00)

Yeah, it will move around a bit normally. But sometimes it goes off the charts and that shows something is wrong.

Alternatively, you could just have bad gas :iono:

You must be running one of the V4 OFT tunes. I don't know how TF they didn't put initial IAM value at 1 :bs: It going to 1 and holding is a good sign.

Take a log and post to datazap. Look for any negative FLKC or Knock Correction (KC) events. Those are the degrees your ECU is pulling from the ignition timing advance to compensate for knock at those specific RPMs and loads.

That said, if your IAM is 1, you probably don't have any serious knock issues.

Alright so update for anyone helping me out or just browsing, after work today I reflashed my ECU(went back to original oem file and went back to stge 2 + 93oct tune). I noticed my IAM started from value of 0.70 as always did. This time omw to school, IAM did not reach to a whole value of 1.00. It ended up only reaching to 0.87 by the time I was at school. I did a few log recording otw to school, few pulls and normal cruise. I will post a log to see if anything’s wrong.

Your going to need to drive the car for a while before a log will be worth it. Since you reflashed the car needs to relearn trims and KC learned. Will probably go up after it gets some mileage on it.

I’m pretty sure my upstream air:fuel sensor is long gone, ltft is seemed to be stuck at 0.00% or some negative value for long period of time without changing the value :iono:

https://datazap.me/u/samthekorean/lo...1-5-8-12-13-14 heres the log data, is my ltft supposed to stuck in certain value for that amount of time?

It looks like ltft is behaving normally. It's averaging about, -5%. If the average creeps up past 10%, then you should start worrying. The two flat spots you see are normal. You were in open loop (OL) in both of those cases. On open loop acceleration, you are in the highest load bucket for the ltft, so it just adds/subtracts the value in that bucket. On open loop idle it adds/subtracts from the lowest load bucket. Notice how stft is flat 0, that's another effect of OL, stft is simply not added. The reason for this is because your o2 sensor is not supposed to accurately read much richer than 14.5. In OL, your afr is likely to be in the 12s under acceleration and off throttle it reports as 20.

Based on your IAM dropping from 1 to .82, it looks like your engine detected a bit of knock but then it got better as it went back up to 1. I wouldn't be too worried on my own car, it happens sometimes. You could try to find better gas. I've found certain stations tend to be better than others for one reason or another.

I don't remember if KC learned is supposed to be an absolute value or not, but it is all positive so I'm sure that says... Something? I don't put much stock in KC learned myself. Unless you are into actual competitive racing, it's not going to make much difference in what your car can do given your gas and environment.

OK here you go:
FLKC is Fine Learnt Knock Correction - Negative is where it is pulling timing, it can only be positive when IAM is less than 1 and is where it is attempting to add timing back in. If successful then the IAM will increase. This is stored in load/RPM regions so if it has added or removed in the past then this will resume from the last stored value.
Knock Correction - Usually known as FBKC (Feedback Knock Correction). This is at lower loads, is as it says and is instant feedback. Only FBKC or FLKC can be active at any one time.
KC Learn - This is the ignition advance map multiplied by the IAM plus the FLKC value. Or in simple terms, how much ignition advance is being added. Not a useful logged parameter IMO.
IAM - If the default value is higher than the IAM at shutdown, then the IAM moves to the default value at startup. The IAM can only increase under certain conditions so it not increasing is not necessarily a sign of an issue. Only if it drops (and TBH if it drops by a reasonable amount) or never reaches 1 would I look at addressing it. If you're happy that you get regular good fuel, I would set it higher than 0.7 and see what happens.

Read Here:
http://www.romraider.com/forum/topic1840.html

Jesus you have no idea how much of this informations has helped me, I’m thinking about gaining more knowledge about tuning I would want to help people/myself out as you did. Thank you brotha

Lol, well I learned most of what I know through the tuning section of the forum here.