5.3L KR during data logging

[CAtaylor]

Has anyone done any data logging on their 5.3L yet? I was doing some logs on the autocal and noticed a good bit of KR sometimes spiking up to 9 and lasting for up to about 3 secs. Not under heavy acceleration, it looks good there, but under normal cruising / driving. Ran the gas out and refilled with a different brand and it is the same thing, both were 89 octane and not cheapo gas. The truck is completely stock except for the 35" tires. I am wondering if this is normal with the DI engines since they are noisy anyway? It is also definitely pulling timing in relation to the KR. Just curious if anyone else has seen this?

[Charlie5280]

Wish I could answer, but I was extremely curious about these on the new DI injected motors.
IMO, because knock sensors are acoustic and just "hear" sound, i.e., the pinging of detonation....I would think this is normal and the ECU is tuned for it from the factory.

[CAtaylor]

Yea, that is what i am hoping, these trucks are so dang quiet on the inside you would never hear it or have any idea it was there. I sent it to the tuner to get his opinion, will update when he gets back to me.

[TJay74]

I am planning on downloading my stock tune in the coming weeks and trying to get my HP Tuners scanner updated to do some logs as well.

[CAtaylor]

Just heard back from the programmer and he said from what he can see it is the fuel. Will keep an eye on it and see if I can find some that make it go away. I am still curious if anyone else is seeing this too though.

[iCryWheniGoPoop]

Just heard back from the programmer and he said from what he can see it is the fuel. Will keep an eye on it and see if I can find some that make it go away. I am still curious if anyone else is seeing this too though.

Where do you live?

[CAtaylor]

Where do you live?

North West Louisiana.

[iCryWheniGoPoop]

I tend to get more KR on winter blend fuels. I haven't put my scanner on my new truck yet because it would be to tempting not to tune it. There are several different grades of winter blends but I'm not sure how much different yours would be down south than it is here in North East Oklahoma. I will throw scanner on truck this weekend and start logging my 5.3.

[iCryWheniGoPoop]

I scanned mine this morning on the way to work, 24 mile trip, 30/70 city/highway but while on the highway I messed with different loads in different gears, even holding 6th gear with my scanner and slowing down to get a good pull through the gear to hit most load cells. I got absolutely 0 KR anywhere. I even did 2 1/4 mile-ish runs when I hit the port road out here which was dead this morning. If you had HP tuners I would have you send me your tune/log file and scanner config so I could look it over and compare.

 

It looks like you only have 35's, no exhaust, no intake, nothing?

 

I wouldn't really be able to tell anything by your MPG due to the 35's but does it seem to be doing about the same as other lifted/big tire trucks? The reason I ask is because there are a few trucks that have been reporting crap fuel mileage after getting the last recall/update and I was wondering if GM had a batch of bad CAL files going around.

[CAtaylor]

Thanks for the info. Not HP Tuners but here is a Snap Shot of what it looks like, this is about 6 min worth. That is correct, 35's with no other modifications whatsoever. I am averaging around 14 mpg on the Highway running 75 and 12.5 around town hand calculated. Average over the last 2200 miles is 13.8 mpg. Compared to what other guys are posting I am very happy with that considering the lift and tires. Hopefully it is just the fuel around here and I believe that could be the case, my 2013 6.2 did the same exact thing. Just odd that no one else has noticed it. If there is someone in West LA that has done any logging I would be curious to see what you are seeing.

[iCryWheniGoPoop]

I seen your IAT was about 77 so I'm guessed that you logged that with Ambient temps around 70* so I scanned on the way home with it also at 70* and did end up picking up some KR. Its not the same as yours, mine is coming on at 2000-2400 RPM's and it doesn't matter what Load I'm under. It is only averaging about 1.5* KR though and maxing at 4*. Yours looks like you are cruising about 55-60 mph with a very light load of about 40g and 1500 rpms, In that area, I am still getting absolutely 0 KR. I forgot that I am still on a tank of fuel that I got on the way home from my trip so I am actually on 87 octane with 10% corn that I got from a Pilot in Central Arkansas Somewhere.

 

I am thinking the same thing as your tuner, probably gas. I will fill up with 91 no ethanol tomorrow and see if it makes a difference for me.

[CAtaylor]

Thanks for the info. I am curious to see if that corrects the issue. The only place I go by (not miles out of the way) that has non ethanol gas is down in Houma, La and most of the time I have filled up before I get to it. My next tank of gas I will fill up with 93 though and give it a look.

[Boombastic]

What is KR.

[iCryWheniGoPoop]

What is KR.

 

Knock Retard, The Engine Management System is equipped with knock sensors that sense any detonation which causes the ECU to start pulling timing from the normal commanded spark advance. From a tuners standpoint, KR is bad, especially on high compression and power adder engines. I have never sent a customers vehicle out the door with a fraction of the KR that these stock engines are producing. I have been scanning/logging on mine ever since I have read the OP's opening post, trying to find out why it is doing it. The only problem is that without being able to edit my Calibration Data due to Warranty concerns, this makes trouble shooting very difficult.

[CAtaylor]

 

Knock Retard, The Engine Management System is equipped with knock sensors that sense any detonation which causes the ECU to start pulling timing from the normal commanded spark advance. From a tuners standpoint, KR is bad, especially on high compression and power adder engines. I have never sent a customers vehicle out the door with a fraction of the KR that these stock engines are producing. I have been scanning/logging on mine ever since I have read the OP's opening post, trying to find out why it is doing it. The only problem is that without being able to edit my Calibration Data due to Warranty concerns, this makes trouble shooting very difficult.

Are you seeing this consistently now? I only got to log mine over a period of one day so I wan't sure to what extent it was. It is kind of worrisome especially with what the service guy told me yesterday about that guys 6.2 he has in the shop with a busted motor. If a tuner went in there and reset the KR sensor settings you could probably crap out an engine pretty quick if they already have these things running that close to the edge. Hopefully it is just the Direct Injection noise interfering with the sensor.