Ok guys well i have a 5.3 FM MPT70 setup in the TA now after the ls1 with sts died....

I had KR problems with the ls1 now i have KR problems with the new 5.3 setup! I hate this KR BS!

I get KR when stall locks up while cuising down the highway. I also just get random KR at lower rpms when throttle is at less than around 50%...

I know the VE tables is not near perfect and there are a few spots that are a little lean. But im not having problems with KR in those areas lol. I will get the VE table cleaned up once i get the KR issue taken care of. The spark tables are butchered down to almost nothing! I just dont like trying to tune when i cant even drive it without getting KR! I wanna get the KR issue figured out befor i continue tuning!

What do you guys think is causing it? I attached a log.

Setup:
1999 5.3, 317 heads, 02 ZO6 cam, ls6 intake
60# injectors (yes they are for sure tuned right)
Front Mount Master Power T70/.96AR
Vig 3600 stall
9" rearend
4l60E
Open Downpipe dumped by starter (maybee this is causing false knock)


Maybee its false but I dont really want to mess with knock sensor settings unless i have to.... gonna try a shitload of octane booster tomorrow and see if it goes away.

 

Youll spend way too much trying octane booster unless you apply like 5 bottles per 1 gallon.

Just find a pump with some race gas 100 plus octane... itll be cheaper and mix that with as little 93 as you can. For the record I have a post here fighting KR and timing too. I got the timing and my KR is not as bad as yours but as soon as i figure out how to log what I need i should be straight.

 

I had KR issues for a while - sensors were the old style, so swapped them out and a lot of the KR went away. Still had some, even after timing changes, so started looking at other possibilities - particularly the cam and converter.Some hi-stall converters are just inherently noisy and can greate enough noise to fool the knock sensors into thinking there's knock when it actually isn't. Had that same problem with my Fuddle 3600 converter - ended up decreasing the sensitivity of the sensors in the rpm range where I was having the problem and problem has gone away now.

Bird

 

I also have been told that LTs banging causes some. I definately get more with my electric cutout open but its just higher same rpm range under load.

 

I was using a 99 5.3 tune but learned that in 99 the sensors were set to sensetive so I copied the settings from an 02 almost no more kr!

 

I lied i took the car for a longer drive and the kr is still there.

tried fuel from a different gas station and did the russ k dekay and attack method and it didn't help much....

I did notice a light vibration at around 60-70 at light throttle. Im thinking it could be a u joint or the DS is out of balance somehow? It is a very light vibration. I just put on new rims/tires and a 9in rear so its more than likely something in the drivetrain/suspension.... But to set off the Knock sensors wouldn't i have to vibrate pretty hard?

I have not heard the car detonate once when i see kr.... thinking i might slowly move the sensetivity down on the knock sensors till i get no kr.


I am running out of ideas! My afr is good and spark is very conservative, IAT's are nice and cool, ECT is 198-210, I am running Dual catchcans so no oil is making its way to the cylinders, oil is also returning to the oilpan good so no oil in charge side, not sure what else could cause REAL KR (detonation)!

The only things that i can think of that may be causing FALSE KR is my downpipe that dumps by the starter or the slight vibration, maybee the NGK 8 racings plugs (gonna pull them and see what they look like).....

ALSO MOST OF THE WOT PULLS I MAKE THERE IS NO KR! lmao, doesn't make sense...

I attached a log from today.....

Here is everything on my setup (if it helps):

Junkyard Pullout 5.3 LM7
MLS head gaskets
stock 317 Heads with PRC Dual springs (giving me like 8.7-8.9 compression)
01 ZO6 Cam
Comp 7.425 Pushrods
ls6 intake
ported TB
FMIC
Master Power T70/.96AR Turbo
Homemade merge pipe/downpipe dumped by starter
60# injectors
NGK 8 racing plugs gapped at like 28 (cant remember for sure)
stock wires till the MSD's i ordered show up
stock tranny
VIG 3600 stall
stock driveshaft
Quick Performance 9" 3.70 posi
3 point subframe connectors, lca's, stock tq arm
summit stars, mt radials, mt skinnies

 

If you reduce timing where you're getting kr by that amount and you still get the same kr it is false knock.

 

I have tried reducing timing to almost nothing and I still get kr....

I wanna pull the plugs and look at them.... if they look ok the sensors are getting turned down.

 

I have an M6 so I can't help as it relates to the auto/stall... but I can say I fought this for a few months. I put in a full tank of 104 and I was still getting 4* KR at many loads. Completely reduced the knock sensitivity, no change. Replaced one sensor, no change... swapped it with the rear sensor...no change. Bought a new sensor harness, no change. Then I broke out the Helms manual (where I should have started). Old sensors tested OK. Wiring harness between sensors and engine harness behind intake tested OK. Engine harness behind intake to PCM pin tested OK. Only step left was to replace PCM. Problem resolved.

 

Looks like false knock, but I would buy a wideband like a LC-1 just to confirm you aren't getting a lean condition.

 

I have an AFX NGK wideband... I pulled it and recalibrated it for an hour to check the afr agian. (just incase the calibration got off and i was actually tuning it lean... but it was still dead on)

It seems alright...

 

anyone have a good place to start to make the sensors less sensetive but not to sensetive that they wont pick up detonation????

 

The knock sensitivity on the stock 02 PCM is already set to 0

 

This is VERY interesting. Do you have any EFI live logs?

 

bump^^^

 

No i dont have any EFI logs.....

Ya im not sure about changing the PCM but man i really dont wanna buy the PCM and then buy the software upgrades for the new pcm... I can buy another motor for that much, lol. I paid $400 for the motor.

It is interesting that the PCm could cause you to have KR all the time though....

 

I was asking the other member if they had any logs.

I was very interested because I am running a 99-00 PCM but I put the 2002 Operating system on it. Therefore it should be identical to running an 02 PCM???

But I was told by a tuner that he's seen bad PCMs cause all kinds of stuff. I know back when I was getting mail order tunes the very first PCM I put in my speedo and tach were going wild. At idle it would say 30 mph and all kinds of crap. So it was a bad PCM. By everything ran just fine. Just the gauges were messed up. SO maybe it's possible the pcm is bad.