jboyss Posted May 21, 2006 Report Share Posted May 21, 2006 OK i finally got my scan gauge reading knock and it doesnt look good. Im reading 7.9 KR and i can FEEL IT! Its like my truck is bogging down when i hit 7.9. How bad is this for my engine? Quote Link to comment Share on other sites More sharing options...
04CHASE Posted May 21, 2006 Report Share Posted May 21, 2006 well considering 8 is the max that it will show thats alot. being blown an having alot of knock its alot worse then a n/a motor. i would definatly get off the throttle as soon as i saw that. Quote Link to comment Share on other sites More sharing options...
adams2003 Posted May 21, 2006 Report Share Posted May 21, 2006 Over time that much KR is definately not good. You should start working on your tune (or have someone else work on it) and try and get it lower. Quote Link to comment Share on other sites More sharing options...
BenKey Posted May 22, 2006 Report Share Posted May 22, 2006 When do you see that much? Is it from a dead stop and WOT? Is it when cruising and then WOT? Quote Link to comment Share on other sites More sharing options...
jboyss Posted May 22, 2006 Author Report Share Posted May 22, 2006 When do you see that much? Is it from a dead stop and WOT? Is it when cruising and then WOT? <{POST_SNAPBACK}> It usually happens when i give full throttle and it kicks down a gear. And im not to sure but it may do it at a full throttle start. Not to sure. Im staying off the throttle for awhile. Quote Link to comment Share on other sites More sharing options...
supersub Posted May 22, 2006 Report Share Posted May 22, 2006 When do you see that much? Is it from a dead stop and WOT? Is it when cruising and then WOT? <{POST_SNAPBACK}> It usually happens when i give full throttle and it kicks down a gear. And im not to sure but it may do it at a full throttle start. Not to sure. Im staying off the throttle for awhile. <{POST_SNAPBACK}> is that with the new tune and smaller pulley? Quote Link to comment Share on other sites More sharing options...
.justin. Posted May 22, 2006 Report Share Posted May 22, 2006 PCMForless Radix Tune by chance?? If so, I'd be willing to bet that is lean knock... Check your narrowband O2s. You should go above 900mv anytime you go into boost. If your tune is like mine, it will stay at stoic until 90% throttle, which is a BIG no-no for boosted motors. Quote Link to comment Share on other sites More sharing options...
jboyss Posted May 22, 2006 Author Report Share Posted May 22, 2006 PCMForless Radix Tune by chance?? If so, I'd be willing to bet that is lean knock... Check your narrowband O2s. You should go above 900mv anytime you go into boost. If your tune is like mine, it will stay at stoic until 90% throttle, which is a BIG no-no for boosted motors. <{POST_SNAPBACK}> Yea it is a pcmforless tune. Its very dissapointing to pay for him to retune my pcm and it still runs like shit. I guess the only real fix is a good dyno tune. Quote Link to comment Share on other sites More sharing options...
BenKey Posted May 22, 2006 Report Share Posted May 22, 2006 Sounds like tip-in KR, from what I know of it. Does it happen all the time or does it just happen occassionally? Quote Link to comment Share on other sites More sharing options...
Krambo Posted May 22, 2006 Report Share Posted May 22, 2006 Sounds like tip-in KR, from what I know of it. Does it happen all the time or does it just happen occassionally? Was thinking that as well (burst knock as well). Zippy, chime in here! Do you have a stall converter in there? I had terrible KR issues on kickdown and a strait flash stall. If I pulled it into a lower gear manually and floored it, the KR was minimal and cleared up quickly. If I power braked before launch, NO KR. I know you have a FP gauge, what is your FP on a WOT run over 5K RPMs. I know the 04's have a more difficult time holding peak FP at your power levels than the 03's. You may be running into a fuel starved motor. FWIW, I still get a little bit of KR from time to time. My tune is aggressive and any little change (varying gas, hot temps / cold temps etc.) wil show a bit of KR that clears up quickly. The worse I see now is 1-2*. Quote Link to comment Share on other sites More sharing options...
jboyss Posted May 22, 2006 Author Report Share Posted May 22, 2006 (edited) Sounds like tip-in KR, from what I know of it. Does it happen all the time or does it just happen occassionally? <{POST_SNAPBACK}> Was thinking that as well (burst knock as well). Zippy, chime in here! Do you have a stall converter in there? I had terrible KR issues on kickdown and a strait flash stall. If I pulled it into a lower gear manually and floored it, the KR was minimal and cleared up quickly. If I power braked before launch, NO KR. I know you have a FP gauge, what is your FP on a WOT run over 5K RPMs. I know the 04's have a more difficult time holding peak FP at your power levels than the 03's. You may be running into a fuel starved motor. FWIW, I still get a little bit of KR from time to time. My tune is aggressive and any little change (varying gas, hot temps / cold temps etc.) wil show a bit of KR that clears up quickly. The worse I see now is 1-2*. <{POST_SNAPBACK}> I first noticed it happening when i floored it on the highway and i wasnt going as fast as i should have been. Kind of felt bogged down. And this is new it didnt happen a couple days ago on the same tune. So i reconnected my scan gauge to test for kr. And now whenever i floor it basically i can feel it and it will read 7.9 kr. The fuel pressure seems to be solid when i floor it, at about 60. Sometimes it will dip a tiny bit lower to maybe 58. The stall isnt installed yet, but it is tuned for one. Could that be my issue here?? Edited May 22, 2006 by jboyss (see edit history) Quote Link to comment Share on other sites More sharing options...
BenKey Posted May 22, 2006 Report Share Posted May 22, 2006 I don't think your problem is related to not having your stall installed. You need to go do some driving and see if it is present all the time. Go from a stop to WOT and then from a cruise, like 45 or so, to WOT and see if it is there for both. If you got the dual aeroforce gauge, which I hope you did, monitor KR and LTRIMS (B1S1) and see what you get. Quote Link to comment Share on other sites More sharing options...
adams2003 Posted May 22, 2006 Report Share Posted May 22, 2006 PCMForless Radix Tune by chance?? If so, I'd be willing to bet that is lean knock... Check your narrowband O2s. You should go above 900mv anytime you go into boost. If your tune is like mine, it will stay at stoic until 90% throttle, which is a BIG no-no for boosted motors. <{POST_SNAPBACK}> Yea it is a pcmforless tune. Its very dissapointing to pay for him to retune my pcm and it still runs like shit. I guess the only real fix is a good dyno tune. <{POST_SNAPBACK}> I had the same problem with brians tune. Zippy helped me out though. Quote Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted May 22, 2006 Report Share Posted May 22, 2006 Couple of things -- first it could be false knock. These trucks ALL will read knock with factory settings on the tranny when it kicks down. Start from idle and give it 50-60% throttle and test for KR. If you see none, try again at 60-70, etc. etc, until you are trying at WOT from idle. If you see no KR during any of these runs, it may just be the standard kick-down knock (which is harmless, but will make your truck perform like crap). If you do see KR during any of these runs, STOP and get some high octane gas (104) and try the same run again. If you still see KR, reload the magnusson tune until you can get it straightened out imo. As Krambo and Ben have stated, it may be tip-in knock, or burst knock as well, but neither of these (or the kick down problem from the tranny settings) generally produce such high numbers. 7.9 KR is an "Oh shit" moment with FI. Can you monitor your narrow band o2s? If you are seeing 7.9KR and anything less than .880mv the tune is screwy and needs to be fixed before you go to boost again. Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted May 22, 2006 Report Share Posted May 22, 2006 Have you scanned to see if you have any misfires along with this KR? I am new to the LQ9, but I ran an L67 with a manudon M90 on it for years. If you have that much KR that isn't false from the tranny issues mentioned and misfires present on certain cylinders, check your plugs, then hope and pray it isn't what happened to me on the L67...cracked piston. At first I noticed it only when kicking it down on the freeway, then starting getting KR at WOT off the line, thought it was false too. I was getting 8+ deg of KR. Then not much longer, BOOM...popped the #3 piston. Happens alot on the L67 with boost (I was running about 12psi). Not trying to scare you and could be totally off, but check for misfires nonetheless. Quote Link to comment Share on other sites More sharing options...
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