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*** Knock, do you have any?


LittleBlueGT

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it shouldn't be running wastegate boost since you're iam is still 1, though you are knocking, sounds funky, could be bad gas, what's you're oil consuption like?

 

Looks like bad gas to me too.

 

Even though it is not captured in the log, you are probably knocking enough for IAM to drop and you to go into WG boost. You should stop doing WOT runs until you burn through that tank of gas. Also, check your throttlebody to TMIC connection too...something is way off with your fuel trims.

 

BTW - while logging immediately before and after a fill up on bad gas, I managed to capture knock everywhere right after the fill up.

 

I went to pepboys and added 2 bottles of the "snake oil" octane booster stuff and it completetly eliminated knock. I used NOS octane booster - to my surprise, it actually worked for me. The knock almost immediatly went away.

 

Good luck.

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Interesting thing; if I drive the car in manual mode it's all good. If I leave it in D, I get FLKC activity and now and then a -2 on the FBKC. The only difference between the two modes really is the revs that the engine sits at when driving around. If I shift manually, I keep it around 2.5K and under 3K for better drivability. When in D, thanks to the dumb AT logic, it will always end up in too high a gear for the speed so the engine oftentimes will be at or under 2K with the torque converter unlocked. My car always ran great during summers, then for strange reasons it would go to shit at random on cold days, something that had baffled 3 tuners. Well, we mirrored the timing adjustments based on intake temp on the cold side as it is on the hotside and so far it's been great, IAM has been stuck at 1. Gonna try zeroing it out, in other words not pull timing as the temps decrease and see how it does.

I finally got a dp installed, I have been running on the gutted stocker with 1 cat left, and it runs better. Boost has been consistent too. Before, it would overboost, bleed off, then build up again, overshoot target, bleed off, rinse and repeat. So far it's been dead on so I may not even have to hook up the Perrin bcs I've had for a year now in my garage :lol:

 

Just sharing my experience I guess.

Edited by fishbone
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Believed I found my problem. My sprak plugs were glazed, plus the octane booster I previous added did not help either. When I pulled the plugs out, all 4 had reddish to yellowish color deposits all over them. After researching the different colors, this is what I found.

 

Reddish color deposits - "effects from octane boosters", research shows some fuel additives which contain octane boosters will leave conductive deposits on the core nose. Avoid fuel additives that contain octane boosters.

 

Yellowish color - "High Speed Glazing", indicates combustion chambers temps has risen suddenly during hard acceleration. Normal deposits melt to form a conductive coating, causing misfiring at higher speeds.

 

Recommendations - Change spark plugs.

 

After changing the plugs it was night/day difference in power and responsiveness. I'll need to data log another run to determine if the plugs were the main problem here.

My wife's balls are delicious.
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I'm wondering how common it is to get spurious knock at cruise. I think there couldn't possibly be a way this is real knock in the attached log, but I'd love to hear what others may see in this.

 

It's knocking at around 4200 rpm at .6 load with the knock sum going from 15 to over 25 in just a few seconds.

 

I don't normally see it increase very much at all (see full version of this file in second attachment). Think it's easy to write off as a false positive?

romraiderlog_20111002_185516_knock.csv

romraiderlog_20111002_185516.csv

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It's pretty common. Several local people have reported it and no matter what adjustments they made, it was always there. I get a few knock sum increments when I'm in top gear and squeeze the pedal steady but firmly and accelerate from about 50 to 60 or so which I realize is not cruise condition but wanted to mention it as well since this, too, seems to be relatively common here. Edited by fishbone
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  • 1 month later...

I've read through this thread and I am trying to understand knock. Please correct me if I am wrong.

 

So there are 3 types of correction in the ECU. Rough (DAM/IAM), FBKC, and FLKC. Each can be active given the conditions. So does that mean DAM can drop below 1 even with no FBKC and FLKC?

 

Lastly, in the log below, I can see the DAM drop when the knock sum increases. That means during that point in time, DAM was the knock correction method? Thus when I see a knock sum increase, there is a drop in the DAM.

 

See log attached when I catch DAM dropping.

datalog8.csv

Edited by authenticamd
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DAM/IAM drops when there is continuous and excessive FLKC.

Knock sum, ideally, should never ever increase. If it is increasing, you need to find out why. If it is increasing at loads over 1.5 or so, chances are it is true knock, especially if you have it floored.

 

LE: in your log, you had it nailed. Not good. Notice the time column. There is a gap between 4.1 and 4.39. This usually happens when you log a lot of parameters, which you're not, you have the ones you need, so not a lot you can do about it at this point. Knock sum says there was only one knock event in that area supposedly, that didn't get caught? I don't think I've ever seen DAM falter like that. This is what I know and I am a newbie so I will let the experts chime in.

Either way, it's time for you to figure out why/when DAM is dropping.

Edited by fishbone
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  • 2 months later...

I'm hoping someone can take a quick look at this log for me.

 

I've been having some bad smells lately and I'm thinking it's a cat about ready to flake apart into the turbo so I don't want to do any hard driving for proper logs, but I'm a little concerned about the knock number...

 

Feedback would be appreciated. Thank you.

 

https://docs.google.com/spreadsheet/ccc?key=0AjWpEyKowFYVdFllMEJsNzJIa0NtMGJkbXMzXzVGUHc#gid=0

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1) That log is pretty useless. You're not logging FBKC, FLKC, or Knock Sum.

 

2) You're logging WAY too many things that have absolutely no relevance whatsoever. Your log interval is 361ms per line, which is over 1/3 of a second. Reduce the parameters. You only need the following:

Engine Speed (rpm)

Knock Sum* (count)

Engine Load (4-Byte)* (g/rev)

Feedback Knock Correction (1-byte)** (degrees)

Fine Learning Knock Correction (1-byte)** (degrees)

Manifold Relative Pressure (4-byte)* (psi relative)

IAM (1-byte)** (multiplier)

Ignition Total Timing (degrees)

Throttle Opening Angle (%)

Mass Airflow (g/s)

Mass Airflow Sensor Voltage (V)

Gear (Calculated)* (position)

Intake Air Temperature (F)

 

I bolded what I think you should have logged at bare minimum, and the rest are somewhat optional. Also, if you are using RR to log, check the "Fast Polling" option up top. This will make things log a lot faster.

 

3) That "Knock Correction" parameter isn't actually knock. It's the amount of Dynamic Advance being applied to your base timing. Read the very post of this thread for an explanation of what DA is.

 

4) What year is your car? There is only ONE cat that is pre-turbo and that cat is in the UP. Later year cars don't have it. 05-06 have it. Anything newer does not.

Edited by iNVAR
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