Stage 2, knock at low load, need an advise.

I've been working on this tune for a week, now all WOT rns looks nice exept this strange knock on a low load, 10-30% throttle opening.

 

Here is the logs (xls file, some coloring added), I've extracted only FLCK and KBCK and surrounding areas.

 

Need opinions from more experiensed tuners regarding possible cause and how to fix it.

knock.xls.pdf

I also get knock in that range, but typically under 2300 RPM, it could be just noise. I think if you log knock sum we could all get a better ide of how many knock events are occuring and exactly when. Right now, i could tell when feedback kc is kicking in, but I don't know how many knock events actually occured.

OK, knock sum logs will be soon here :-)

From what I have read, knock that occurs in that range is most likely just noise for 2 reasons.

 

1 - Tuners do not usually alter that portion of the map, the timing/fueling in the low load/low rpm is usually exactly like stock.

 

2 - In low RPM situations, the ecu has a hard time differentiating noise from knock. It does a better job above 3,000rpm.

Ok, I see. thank you for explaining.

BTW, I can't find a knock sum on romraider logger.. Is it named differently?

Ok, I see. thank you for explaining.

BTW, I can't find a knock sum on romraider logger.. Is it named differently?

 

It is an SSM parameter (not that I know what that means) and needs to be connected to the car to be available to log.

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I've connected RR to a car, but nothing like SSM paramter is there.. Very strange.

Also, I've get newLerning view, FLKC 1.4 is gone , but thre is a new one. Looks like I neet to drive more to get more leraning. Will post results soon. Here is the current logs (no SSM, though), and Lerarning view.

 

It gets warmer , first log was at about 35F around, second at 55-60.. I may get even more knock with higher temps.. How I can fix it? only timimg?

second.csv.pdf

It is an SSM parameter (not that I know what that means) and needs to be connected to the car to be available to log.

 

Knock sum is not an SSM parameter.

 

It is an "extended" parameter which means it's something that merchgod found by poking around in the rom. Not all ecus have it so you have to hook up the car first so that romraider can list the extended parameters unique to your ecu.

I am experiencing the same problem too. My tuner assured me that it was most likely noise but I have just made him lower the timing a little anyway just to see if it would make any difference.

Ok, I see. thank you for explaining.

BTW, I can't find a knock sum on romraider logger.. Is it named differently?

 

Make sure you have the latest logger definitions. While online, open romraider logger, then got to the top menu Help>Update logger definition. This will link you to romraider page that has the latest defs, they are dated 10/3/08. Download the file and follow the directions.

Got it! The problem with KS was a missed def.

Here is the log with knock sum. Do not sure how to interpret it right, I have about 20 knock events during 15 min city drive.

third_with_ks.csv.pdf

Knock sum is a great tool. Every time you see the number increase, that means there was a perceived knock event. So, for example, when your knock count goes from 1 to 2, that means that there was a knock event at that exact point (when it increased from 1 to 2). It will then stay reading 2 until another knock event happens (increasing the count from 2 to 3 and so on).

 

Keep in mind, I am still learning this stuff myself before you read below, I am no expert.

 

Okay, I took a quick look and about 90% of your knock is at idle and the rest of the events are at around 2,300 rpm (which falls right in line with your learning view). I suspect something is rattling around near the knock sensor. But then again, I suspected the same thing on my car and I can't find it, you should check and make sure everything is fastened down.. BTW, you should keep the time marker column on your logs, so we could direct you to specific examples.

 

As for solutions:

 

- You could live with it, it is likely not knock at all (but there is no way to tell)

 

- You could have your tuner raise the knock correction thresholds. In other words, the ECU will ignore knock below 3,000 RPM (for example) and not pull timing. i think factory is set to ignore anything below 1,800 rpm.

 

- You could have your tuner pull some timing in the area (2,300 rpm) that you have the most knock. Keep in mind that most tuners do not change the timing in that area, it should be the same as stock.

 

If it was me, I would just live with it unless your IAM starts dropping. Have you checked you IAM lately, make sure it is at 1.

The normal driving around knock seems a bit much but I don't think it's a problem either. I was told that if you were to log 100% of your driving you would see this. As long as you're not seeing it on WOT logs it seems okay.

Knock sum is not an SSM parameter.

 

It is an "extended" parameter which means it's something that merchgod found by poking around in the rom. Not all ecus have it so you have to hook up the car first so that romraider can list the extended parameters unique to your ecu.

 

I don't even know what SSM means.

 

I do know that it has to be hooked up to the car to get many of the various items to log.

I have been paying with this for well over a year, couple of things:

 

When it is cold (coolant temp timing comp table) the ECU adds a ton of timing. I don't know if that is it, but I can get 60 knock counts just pulling out of the parking lot at work when it is 10F outside.

 

You can change the knock thresholds for FBKC and FLKC (and even the area that the ECU uses to determine changes to the IAM). I wouldn't change it to 3000 rpm though, our little turbo hits peak boost at 2800 rpm!

 

I would change the low end of the load window, ie: tell it not to listen to knock below load 1.3 or something like that.

^Thanks, I'll try to do this. After more dtalogging.

Now the scary story: Driving today (55F out), was running on 4rt , about 20% throttle.. felt loss of power for a several seconds.. Log showed.. -12 FLKC!!! Knock count jumped from 19 to 25, then to 30.. That was scrary..

I've post the log (colored knock areas, orange - scary one).. Any idwas what could happened? I've tried to replicate the same situation again and again, all was normal after this.

 

First LV right after that drive, second - 1 hour later..

Wondering what it was..

^Thanks, I'll try to do this. After more dtalogging.

Now the scary story: Driving today (55F out), was running on 4rt , about 20% throttle.. felt loss of power for a several seconds.. Log showed.. -12 FLKC!!! Knock count jumped from 19 to 25, then to 30.. That was scrary..

I've post the log (colored knock areas, orange - scary one).. Any idwas what could happened? I've tried to replicate the same situation again and again, all was normal after this.

 

First LV right after that drive, second - 1 hour later..

Wondering what it was..

 

The lv does indicate a little bit of high load knock at mid rpm, I would capture this in a log and address it. ( no biggie though)

 

Where is the log?

 

I used to get -12 FBKC at real low rpms and load too, I just eventually changed the parameters in the ECU so it wouldn't happen anymore.

 

But first, I checked my timing against many others (inc stock), then I checked my AFRs with the stock sensor and a WB, then I gave up and tuned the problem to disappear.

 

FWIW the colder it gets, the worse it gets.

Ops, for some reason log was not attached.. Here it is:

 

As you'll see, it happened at relatively big load (over 2g/rev).. Right after boost jumped from vacuum to 10.

bad_knock.xls.pdf

Oh, and it was FBKC -12, not FLKC..

Are you sure nothing is loose under the hood? Check for rattling vac lines, or anything else near the TMIC. Also, is your IAM at 1?

yes, its stays 1, as you can see on LV. I did not log it though.

I'll check tonight if anything got loose.. .

Oh, and it was FBKC -12, not FLKC..

 

 

Yeah, something seems wrong there.

 

Try putting in a tank of racing fuel or something (octane booster is a joke, unless you buy 10 bottles) like torco and see if it goes away.

 

The timing and AFR both seem fine, and at 3000 rpm and 1.3 load that is crazy FBKC!

Just to cover all the bases, maybe you should flash back to stock and do some more logs..

It is already went away, as I can't re-produce it again. I've spent 15 minutes running same gear, same speed and throttle, and had nothing like this.

I'll monitor it for a several days, if it won't go back i consider it as.. bubble or piece of sh&t in fule lines? who knows.. will see. Hope nothing was broken.