Crazy KR under light load.

[MADWHIP]

Hi all,
Ok so I need some advice. I'm tuning a 2012 HSV Maloo with a LS3 today. The car is now fitted with a high lift camshaft. Before the car was fitted with the cam it was activating it knock retard at idle and any light throttle. It made no difference if it was in gear or park/neutral. The knock pattern does not look like normal knock and I certainly can't hear any. I have attached a data log that shows what I'm talking about at 14:58.40 I have also attached the tune used to make the data log. When I load the ute up for a power run this knock issue goes away. And yes I have decreased the sensor sensitivity not something I do lightly but wanted to see the effect on this issue. It made very little difference. I have looked over the ute and the exhaust does not seem to be contacting the body at any point. Any input welcome.

[5FDP]

Hmm, that knock is weird.


Curious question though, is this setup MAF-less??

I ask because the MAF sensor data is at zero but the tune is not correctly setup to run speed density. The MAF high and low fails aren't setup right and the MAF dtc's need to set to first error.

[MADWHIP]

yes Mafless. The knock issue was there when this was stock and is obviously still here now. But yes 2 bar sd os now. Thanks for the heads up.

[MADWHIP]

Anybody else have anything?

[mowton]

I would say remove 2 degree's in the 0-2000 rpm and .08 to .40 g/cyl and see if you get the same...if so, it is false and you might have a header/exhaust etc rubbing up against the chassis somewhere.

Ed M

[schpenxel]

Had a power steering pump going out on mine that caused this once...

[MADWHIP]

I did pull timing to no avail. I'll have a look at the power steering pump. cheers for the suggestions guys. I'll report back with what I find.

[schpenxel]

Long shot but worth at least checking

[mowton]

I did pull timing to no avail. I'll have a look at the power steering pump. cheers for the suggestions guys. I'll report back with what I find.

So it sounds like false knock so you can either find the source and repair if repairable or desensitize the sensors in and around the area you are experiencing it.

Ed M

[MADWHIP]

I'm going to make sure the knock sensors are bolted down and not just bouncing around. I can't say I have ever had to replace a knock sensor on a ls before but I would like the car to go out fixed rather than the problem masked. cheers guys.

[07GTS]

i was looking at a tune a little while ago ls3 stroker where it basically always showed knock steady 2 odd deg as soon as the vehicle moved and only stopped under decel and with decent throttle input, tried a heap of changes tune wise but nothing helped, im not sure if a fix was found but he was looking at knock sensors and exhaust last i herd

[10_SS]

I'm confused. I downloaded the same log file which shows 175kb, 48 seconds long. veiwed by 13 people. I see 0.0 KNOCK RETARD the entire time. You guys are looking at SPARK RETARD somehow, even though it doesn't show up in the channels list. This must be something like Total Retard.

Either way, maybe you could add more knock retard PID's and narrow down what exactly one you are seeing. If it's an E38 with an LS3 like mine and CC-rider and mostly stock burst knock values and you disable MAF which looks like you did then you may get tons of false Burst Knock retard, which I don't see logged.

Now, What's interesting in my scanner is my Knock Retard in the channels and chart show 0.0deg retard the entire time, HOWEVER, my Graph (histogram) shows retard... further investigation shows my Graph (histogram) is setup to show SPARK RETARD, not KNOCK Retard. Spark retard must be all retards... not just knock retard.

Now I realize exactly how this happened... when adding "KNOCK" retard to the Graph(histogram) and it asks you if you want to use Generic Sensor... if I choose YES, then it changes it to Spark Retard... if I choose NO! I know what I'm doing! keeps it correct. I hate that window.

Good thing I haven't been tuning spark based on knock retard using the histo's!

I have a feeling SPARK RETARD is something like TOTAL RETARD, and not in any way related to Knock Retard.

[mowton]

I'm confused. I downloaded the same log file which shows 175kb, 48 seconds long. veiwed by 13 people. I see 0.0 KNOCK RETARD the entire time. You guys are looking at SPARK RETARD somehow, even though it doesn't show up in the channels list. This must be something like Total Retard.

$hit......Good catch, I just got caught with the Generic Sensor YES or NO, I KNOW WHAT I'M DOING! question as well :-( If you log Knock Retard in you channels, when you load to your Chart and you answer YES to the Generic Sensor question popup, I just saw it changes it from Knock Retard to Spark Retard....shit......all this time I have been logging Spark Retard instead if Knock retard.........

Thank you sir for showing me the error of my ways.....

Ed M

[10_SS]

$hit......Good catch, I just got caught with the Generic Sensor YES or NO, I KNOW WHAT I'M DOING! question as well :-( If you log Knock Retard in you channels, when you load to your Chart and you answer YES to the Generic Sensor question popup, I just saw it changes it from Knock Retard to Spark Retard....shit......all this time I have been logging Spark Retard instead if Knock retard.........

Thank you sir for showing me the error of my ways.....

Ed M

yea this is pretty crappy. Like I said my histogram was messed up all this time. Apparently everyone on this thread was too. HPT, can you just get rid of that window??

[schpenxel]

Guess I should have looked at the log prior to responding

Knock retard != to total knock retard

[10_SS]

Guess I should have looked at the log prior to responding

Knock retard != to total knock retard

you mean Spark Retard = Total Knock Retard? That would explain it

[schpenxel]

Yeah, the generic spark retard parameter appears to be = total knock retard. I haven't tested it but it seems to line up

[mowton]

Yeah, the generic spark retard parameter appears to be = total knock retard. I haven't tested it but it seems to line up

So if that is the case than how can you give the choice for a generic sensor or not which completely changes the function of the parameter........Aggggggggggggh

Ed

[schpenxel]

I could be wrong... but appears that is the case by the log or two I looked at

[10_SS]

So if that is the case than how can you give the choice for a generic sensor or not which completely changes the function of the parameter........Aggggggggggggh

Ed

Yea... I never understood the "use generic sensor instead". Well for now on it's always "DO AS I SAID". 3.2 is good, but also bad. They need to fix this.