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Knock issues, driving me nuts!

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Old 09-24-2006, 07:57 PM
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Default Knock issues, driving me nuts!

I dont want to keep reposting stuff so if you guys dont mind I will just link you to the threads i started at PT.net and at EFILive.com that decribe my problems. I am having some very odd knock problems with my truck. You can see in my signature, its a 2003 8.1L/Allison with a Whipple on it.

I get KR all over the place but its not always consistant. I have tried several tunes with spark tables in the single digits and i still get KR. Just keep in mind my base tune is from my old tuner so i dont know all the in's and out's of it, but i have been using it to makes changes but im not having a whole lot of luck. I have never actually "heard" the ping so in the back of my mind i am hoping the majority of this is false knock. I have done most of the basic stuff like tried different gas stations, tried 104 octane booster, drove by jersey walls to see if i could hear any pinging and nothing has worked. I have a few people helping me out but i know they have thier own life too, so i am trying not to bug them to much. I just got EFILive a few weeks ago and am learning as much and as fast as i can so i will try to follow the best i can if any of you have any suggestions for me to try. I am just trying to patronize as many people as i can with this to get some answers. I have posted a couple of tunes with thier associated logs in those threads. Thanks in advance for any suggestions you have.

http://www.performancetrucks.net/for...d.php?t=375152

http://forum.efilive.com/showthread.php?t=3486
Old 09-24-2006, 10:04 PM
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Sounds like it couls very well be false knock, try desensitizing the knock sensor and see is you can detect any pinging.

I didnt know those walls actually carry the name "jersey walls", pretty funny.
Old 09-24-2006, 10:24 PM
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Originally Posted by brad8266
Sounds like it couls very well be false knock, try desensitizing the knock sensor and see is you can detect any pinging.

I didnt know those walls actually carry the name "jersey walls", pretty funny.
They are set at 7.90 right now. What would be the best setting to change to?
Old 09-25-2006, 11:54 AM
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This might help:

Originally Posted by 2xLS1
Attack vs RPM - How fast KR is added. Lower #s = less agressive. Try multiplying whole table by a percentage. (.xx)

Decay vs RPM - How fast KR is removed. Higher #s = faster KR removal. Try multiplying whole table by a percentage. (1.xx)
Old 09-25-2006, 01:44 PM
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Thanks Brad, unfortunately i dont have those specific tables in my .tun file. I have a 2003 8.1L and have found it to be quite different than the Vettes and F-body's as far as how they are set up in EFILive. There are a lot of settings in the knock tables, but i dont want to go in there and just start changing stuff till i have an intimate understanding of what they do. Knock sensor multipliers (TPS, RPM), Knock sensor filters, etc. The one that has me scratching my head is the Knock sensor filter. Mine is set at 7.90 and all the other tunes i have looked at are set at 4.70. I will end up just changing it to see if it has any effect, but i was trying to find out what the higher setting (mine) did. Does it filter more at 7.90 or does it filter less? Trying to read up as much as i can.

Last edited by Whippled 496; 09-25-2006 at 01:50 PM.




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