Lunartick

Just wanted to take this moment to thank Dave B. @ CryoTune Performance for his great help to dial-in an ideal 1st stage tune on my beloved LGT.

I would recommend Dave to anyone looking to play it safe and get a Professional road tune for their ride, regardless of what make of vehicle they drive. Dave is an expert in datalog analysis and provided ample safety cushion for the 5EAT Stg1 tune (esp. in Target Boost and Base timing) to reduce risks of blowing a motor due to the presence of a massive restriction in the downpipe. He truly went the extra mile and ensured that the tune was safe for the long haul by having me drive around for a couple of weeks without resetting the ECU, and then recording a couple of WOT logs in 3rd gear. He was always prompt in sending the next rev. and very patient and detailed in his explanation of what he was doing. The high quality of his service certainly justified his modest price of $150

For anyone interested, we determined that the phantom knock was caused by one or both of the following:

1. A small boost leak

2. It appears something is making the ecu pick up knock in low loads that we have not been able to adjust. At 2400 rpm at light load and transitioning into acceleration which is causing the trans to kick a tad and cause the feedback. There is no way we are running too much timing or lack of fueling in that range.

So now the scenarios where I'm used to seeing knock, and not worried about, are:

1. Transitioning into acceleration (with Auto trans AKA 5EAT)

2. Letting go off the pedal

3. Front driver-side suspension rattle/clunk (happens seldom)

4. General knock noise during cruise/low engine load

My car is behaving rather strange today during commute this afternoon, and the FBKC is absolutely off the charts (less than -11 degrees at some point ). Today has been the warmest day since I started this whole tuning business.

Under light acceleration the engine feels like the fuel is being cut and acceleration becomes slightly intermittent. Could it be a bad fuel pump or clogged fuel filter? The fuel is rich. How about a leaking stock TMIC? What else could it be?

I am going to avoid WOT acceleration, and flash the stock ROM until I address this problem.

Below is the alarming log which was started during cruise. No WOT acceleration prior to this. Another log taken shortly thereafter and LTV captured between the two logs.

Log #1

LTV

Log #2

I flashed the stock ROM sometime ago and no sign of knock even under WOT. So I then contacted Dave at Cryoperformance and went on his stg1 map. Huge difference in lack of knock compared to MickeyD's map.

In my extensive searching on the issues of false knock, there have been instances where suspension noise was triggering it, usually bad swaybar endlinks.

I found this to be absolutely accurate. Please see attached snip.

Here's what happened:

I left work with IAM at 1. Drove through the rough section of the parking lot and the front driver-side suspension started rattling/clunking. Drove less than 5 minutes then pulled over to take a look at IAM. What I saw was rather disturbing.

Not trying to say my ECU would've been perfectly happy with MickeyD's stg1 map if I hadn't had clunking and rattling in the suspension, but on Cryo stg1 map all the Learning Table Values are 0 and the lowest FBKC I've seen so far were -2.11.

Initial 2nd/3rd gear WOT logs are attached for your viewing pleasure.

2ND.GEAR_WOT_20140327_184704.csv

3RD.GEAR_WOT_20140328_083253.csv

Before attempting to read from or write to ECU using ECUFlash, you must make sure the GREEN test leads are connected under the glove box and passenger side carpet. Once connected and when ignition is switched to ON you'll hear the radiator fan turn on and off over and over again, until you press read or write on ECUFlash, then the fan stops.

That's the procedure I have to follow on my USDM LGT, I'm tended to assume that the same applies to JDM vehicles.

Ok so based on your rear diff experience, we can safely conclude that the knock sensor is prone to drivetrain noise as well. How about road noise or 'clunking' in the suspension? Could that kind of noise also trigger the sensor?

Assuming that the knock my ECU is seeing is noise: Does anyone foresee any serious consequences for the engine while the knock control sys is pulling timing (through either FB or FLKC) while it didn't necessarily have to, i.e. there was a false incerement (or a few false incerements) of knocksum due to drivetrain or rattling noise?

I remember reading on this post on RomRaider forums by NSFW says less timing is better. Is less timing always better?

I know for sure it's not the turbo heatshield since I made sure that's installed securely (with ALL of the fasteners that come with it) when I serviced the turbo circa mid-February.

I'll try the fist-bang method, and also drive next to a wall with the windows down. Thanks.

Good idea, I'll flash back to the stock ROM and take some logs and see what we're dealing with.

Is there any other sure-fire way to find something that may be rattling underhood?

If not something rattling, then do you know how easy is it to get to the knock sensor to inspect it? I found its position in the service manual, not sure I understand the removal process.

A snapshot of that last log I posted is below.

I see severe knocking at around 3K RPM / 1.4 g/rev combo, total ignition timing is pulled way low to only 11 degrees. -2.46deg FLKC is applied as well as FBKC, meaning that this is not the first time during the commute that the ECU sees knock at this range. This is with good gas, IAM is 100% and A/F learning is 0.

How should I address this issue? How much timing would you advise I should pull from Base Timing?

Some of that knocking is really bad, some isn't. You shouldn't be going nuts mixing your logs if they're on different tanks of gas.

Thanks iNVAR, lesson learned!

Your 2 logs that start with FBKC show a lot of timing being pulled, AND your IAM is already below 1, at one point hitting 0.6875, which means you were knocking a LOT. Did you refill with new gas after that? Because I suspect you had crap gas in there.

I believe you are right on with your observation. I started thinking the same thing yesterday before you posted this and you are probably correct! I try to consistently refill with Mobil's 93 octane gas now which imho is the best I can find around here. However I do believe, beyond a reasonable doubt, that around that timeframe (March 4th,5th,6th logs -- flashed the stg1 basemap on March 3rd) I ALREADY had 91 octane in the tank and wasn't paying attention to this detail. I also filled a half-tank sometime last week from a gas station (not Mobil) in the ghetto, which was labeled 93 octane but who knows what crap they actually got in there.

If it was bad gas, that sort of only leaves us with 2 log files. The first log file you posted (in your first post) only shows one FBKC knock event and it occurred when you lifted off throttle.

I beg to differ. Snapshot of the first log I posted in my first post romraiderlog_20140311_182613.csv is below. I try to lift or press very gently on the throttle, but this knock happened at constant WOT. Throttle opening angle was held at 100% for another ~0.3 seconds after the knock occurred.

I believe you were referring to the knock shown on FBKC_20140305_130659.csv due to the abrupt change in throttle, I can't disagree on that one. Snapshot is below.

Your second log (BOTH FBKCFLKC) shows OLD FLKC (because Knock Sum doesn't increase) which is probably from the bad tank of gas. The FBKC in that log is also in a completely different area than the very first one you posted.

I agree, the knock and ensuing FBKC is at low load RPM/throttle so I'm not too worried about that. More snapshots shown below.

So reeeeeeally, if it was bad gas, you have 1 log showing FBKC at WOT... And maybe not even that because there might still be some bad gas mixed in. If none of this was bad gas, then yeah, you'd have a problem. Get back to me.

I am at least 85% sure it was bad gas (91 octane) but since I was freaking out yesterday I re-flashed mickeyd's stg1 map w/ a modified base timing table. Snapshot of the changes made is below.

I reset my ECU, filled-up on 93 octane gas from Mobil (tank had less than a quarter of the older gas) drove at WOT a little bit on my way home and logged it. Please see my yesterday's post-flash logs attached and let me know what you think. I had to shorten down the 0_WOT_log... size was too big since it was my whole commute.

EDIT: I am posting another post-flash log from yesterday where there is knock. Please take a look, thanks! romraiderlog_20140314_183923

0_WOT_log_20140314_192820.csv

mild_acceleration_20140314_194153.csv

romraiderlog_20140314_183923.csv

Please take a look at this log with FBKC also (attached). Seems that I definitely need to adjust timing at 4k to 4.4k RPM and 2.45 to 2.70 g/rev load. Sorry I didn't log FLKC on this one.

I would really appreciate if someone knowledgeable could advise how much to subtract from Base Timing cells.

I guess good news is that I am not seeing any FBKC at lower RPM's and high load. I'll try to keep the RPM's down during daily driving until I have adjusted base timing @ 4k and above RPM and high load.

Thanks!

romraiderlog_20140306_182559.csv

Your AF Learning #1 indicates that it's pulling a small amt of fuel but is within accepted normal range I think (my tune disables this at high load). Do you usually see FLKC being applied in the same load & rpm range (~2.5 g/rev, 4200 rpm region)? If so, you might want to consider reducing timing slightly in that load/rpm region (Base Timing table) and smooth the values in neighboring cells.

I do not usually see FLKC at that RPM/load but then again I have not been driving or logging at WOT that often to know for sure. What I do know for sure (w.r.t. FLKC) is that it occurs at ~1-1.5 g/rev load / 2k-3.5k-ish RPM. Some LTV table snapshots are attached.

I would like to take back what I said regarding FBKC showing up only once so far. I went through my log history and found more, which is probably a REAL cause for concern. Please see attached. At one instance even knocking twice or more in a row (lower load than 2.5g/rev) !!!

Also attached is a log with both FLKC and FBKC being made: I am suspecting the FLKC's are learned corrections since knock sum does not increment. It does increment for the FBKC however.

FBKC_20140305_130659.csv

FBKC_20140307_070820.csv

Both_FB.FLKC_20140313_180435.csv

Hello all,

I have so far been learning quite a bit from all the great resources on this forum as well as RomRaider's, thanks for all of your hard work and info sharing.

I recently flashed MickeyD's Hawaiian stg1 basemap and have been logging extensively with VAG-COM/RomRaider my daily commutes and relatively short WOT runs. Haven't gotten the chance to log in 3rd gear from 2k RPM to redline simply because I have not so far had the balls nor the opportunity to do so on a public road.

The reason I am writing here today is that I came across one (and only one so far) instance where my ECU used FBKC at high load (~2.5g/rev) to mitigate knock; I've kept a close eye on these two columns and I usually see FLKC used, this has been the first time I see the ECU applying FBKC to timing. Log is attached.

I would like to fix this potential issue so if you could please help me with which table/cells to adjust... Is it base timing at that nasty knock RPM/load area?

Btw I'm driving 05 LGT Ltd. 5EAT since April 2009, just in February I put in a new CHRA from ebay, new OEM banjo and OCV myself since the stock VF40 snapped at the shaft close to the turbine wheel (go figure). Thought about a BNR 16G but was out of my budget at the time.

Again, thanks much.

romraiderlog_20140311_182613.csv