help with KR on 09 equinox

[Vbb1994]

09 equinox, e38. 87 octane, daily driven. no mods. bone stock. high knock and what seems like higher fuel trims than the last time i did a log? i was initially just scanning looking for something else, then the high amounts of knock retard alarmed me. i have attached several logs, just the basics. and the base model tune. only thing ive done thus far is verify my fuel pressure holds 58-61 psi all the way up to 90 somethings kPa. dbw ecm.

i visually inspected motor mounts... all seem fine.. motor isnt loose either.... knock sensor does seem touchy. if heat expansion occurs (pop) it detects it and retards timing. light or heavy tapping near or on the manifolds gets action. i noticed today during my drive, it seemed like i could hear a tinging under the hood that correlated with the KR, except it didnt really... it was very very hard to hear over general road noise and the insulated car. i know what knocking and pinging sounds like and this didnt sound like it ... to be honest its the similar ting it makes when the car is cooling down or heating up....... if i hit potholes in the road it would detect it as knock too.. only reason im seeking advice on this is, ive read about touchy KR modules on certain models, and would like a better informed eye on the logs and tune and to tell me if they see something really obvious before i start replacing parts.

it seems to occur 2500 range, 80-100 kpa, and will steadily hold KR even thru decel until a certain speed.. im unsure if this is just ... normal? bad gas? it did default to low octane. ive got the battery pulled.

thanks guys.... new guy here... posted a couple things, not new to tuning, just new to the p04 and e38.

hope to hear back from yall.

[Vbb1994]

ive battled with high cylinder pressure, low rpm knock before, and pondered if i have leaky injectors dumping too much fuel maybe causing it to knock? i have no wbo2 so its not easy. the o2 Mv seem fine during pulls. they just swing in a very unusual wave form at idle or cruise like its having problems. my well tuned 3100 doesnt do that lol

[Kapem23]

Did you ever get this solved? If there is not anything wrong mechanically , you could try to adjust the SOI and EOI, along with increasing the DC on the fuel pump.

You could pull timing in a specific area by KR graph. Engine speed in the column and cylinder airmass in the row, with spark retard sensor as your parameter.
Then use paste special- subtract.

As a last resort you could desensitize the knock sensors.

[Vbb1994]

Did you ever get this solved? If there is not anything wrong mechanically , you could try to adjust the SOI and EOI, along with increasing the DC on the fuel pump.

You could pull timing in a specific area by KR graph. Engine speed in the column and cylinder airmass in the row, with spark retard sensor as your parameter.
Then use paste special- subtract.

As a last resort you could desensitize the knock sensors.

I cleaned the MAF meter real good, replaced the knock sensor, cleared LT and reset the battery and it mostly definitely corrected the wonky fuel trims and high knock retard, however it still persists. Like if you REALLY get on it it'll get as high as 6-7? KR

Aggressive tip-in seems to do about the same thing.

Whats SOI and EOI?

Thanks

[Vbb1994]

I cleaned the MAF meter real good, replaced the knock sensor, cleared LT and reset the battery and it mostly definitely corrected the wonky fuel trims and high knock retard, however it still persists. Like if you REALLY get on it it'll get as high as 6-7? KR

Aggressive tip-in seems to do about the same thing.

Whats SOI and EOI?

Thanks

Oh and i put a tank of mid grade in, which definitely decreased it.

Spark plugs changed as well. I dropped down to a cooler range. The plugs indicated the cylinder was a little too hot for the range installed.

[KillboyPowerhead]

The LFX engine shows a lot of knock with the factory knock sensor sensitivity and I imagine your engine would be similar. I originally had a tune done by Overkill and he jacked up the sensitivities (made less sensitive) by 10 - 30% everywhere. I'm guessing he spent some time on a dyno with whatever engines/cars he tuned and so knew it was safe to do this. While doing my own tuning I set the knock sensors back to stock to see where I'd normally get knock, and saw quite a bit, and then even after reducing spark timing by as much as double the KR I was seeing I still saw quite a bit of knock, and in many cases saw the same amount of knock, so I figured the engine wasn't actually knocking and was comfortable going back to his settings. Was also using the factory spark tables (tuned for the recommended 87) for a bit and using 91 gas and still saw lots of knock.

If you normally run 87, try a tank of 93 or higher and see what happens (try replicating as many scenarios as you can, because sometimes I'll see 4 - 5 degrees knock on a WOT pull, for example, and other times I'll see none). A whole tank of higher octane should get you plenty of data to compare. If knock reduces or goes away with higher octane then it probably is real; if the same amount is still present then it's probably not real and then you can reduce the sensitivity of the sensors just enough to get rid of the typical KR you see.

SOI is Start of Injection and EOI is End of Injection, referring to when the fuel injectors open and close. If you haven't done many or any mods to the engine you shouldn't need to touch the stock values.