ECMlink What caused this knock??

[onefast2gdsm]

Well I was on it in 5th gear and my check engine light came on, figured it was about a degree of knock or so. Well, turns out it was over 12 degrees. WTF? Ive never seen knock that high in this car. It is towards the end of the log, please let me know what you think.

File too big to upload to tuners. log.2011.11.07-01.elg - 4shared.com - online file sharing and storage - download

 

[XiKeiyaZI]

Step 1 : Check the Sensor. Check for goo on the back of it, check to make sure it didn't rattle loose a bit, and check the wiring.

 

[onefast2gdsm]

The sensor is literally 3 days old. Ill check to see if it cane loose but I doubt it did. Defective sensor maybe? My pulls I did the first night installed were knock free.

 

[onefast2gdsm]

After looking at it closer, my target AFR went from 10.5 to 9.9, yet my openloop is targeted for 10.5. I think my ecu saw this and that my actual afrs were now lean, and retarded the timing. Why would the target AFRS drop like that? I've never had that problem...

 

[XiKeiyaZI]

Heat and vibration likely either allowed some wiggle room in the plug or vibrated the knock sensor a tad loose. I had the exact same thing happen on my GST, last Talon, and Current Talon.

 

[onefast2gdsm]

Well why would my target afr drop?

 

[XiKeiyaZI]

Because your car is stupid!

No idea just yet. Just note that knock sensor first and we'll go from there.

 

[rlacasse1]

Because your car is stupid!

No idea just yet. Just note that knock sensor first and we'll go from there.

I think you nailed it Keiya.

 

[snowborder714]

Next time just clip the log to the problem area, as I'm sure we don't need a log that's too big to upload here to focus on one issue.

I'd also change the Knock Sensor Control settings (ALS/Knck tab) to 2250 RPM and 25% TPS. This will help prevent any phantom knock.

The drop in AFR is interesting, but I would see if you can replicate it after checking out the knock sensor. It looks weird, but your wideband AFR doesn't change that drastically and your SD table isn't messed up around there. It might have just been a hiccup.

Also, please note that you have a DTC code being thrown.

 

[XiKeiyaZI]

I always set my knock sensor activation for 3K+ and 45%+ Throttle because that's usually the only times that I'll ever seen boost. However, Brians suggestion here is Vital. Most of the time, especially when cruising or idling, knock readings are just Phantom knock accounts.

 

[onefast2gdsm]

The dtc is for the Saturn alt swap. Ill try the thing suggested for phantom knock. Ill also try to replicate it tonight, hopefully it doesn't happen again. Thanks guys!

 

[snowborder714]

Download the file here to fix the Saturn alternator DTC.
direct_access_changes [ECMTuning - wiki]

 

[onefast2gdsm]

Thank you all for being so helpful. I will post results as soon as I take it for another spin. I did however check my knock sensor and its tight and everything looks fine.

 

[onefast2gdsm]

So took the car out last night. Every gear had atleast a blip of .4. Get to 5th gear, and same thing happened.. target Afr dropped, wideband reading stays the same, and knock went to 11.4. This is the only gear it does it in. What can be causing this?

 

[Calan]

Post up another log.

 

[onefast2gdsm]

I will when I get home tonight around 8pm.

 

[95gst96gsx]

I've been experience a simliar problem but my car has been knocking on and off recently. It doesnt matter what gear i'm in but right around 2-3k it knocks like crazy from 12-15* and as soon as i let off the gas it goes away and will come back on as soon as i get back on the gas. Right after 3k thought it doesnt knock anymore! Any idea? Heres a clip of the log