Can knock Sum detection pull boost?
#1
Can knock Sum detection pull boost?
I am working on a problem I am having with a CEL posting P0325 continuously. It happen during a track day at Fontana. I have posted in advanced, but this is NOT a cross post; this is a very pointed ECUFlash troubleshooting question. Since I am trying to log to figure out if the answer to my problem is in the log data.
I have attached 3 short/simple logs for review. My basic question for the gurus is:
If knock is detected, in this case 9 from 0, does the ECU bleed off boost as a precaution or does it only impact timing?
I see in my logs that I go from 0 to 9 counts of knock instantly, and it stays there. I don't here any in the car. I see that when this happens the boost is killed off. So is that ECU action or does that indicate a boost leak?
I am trying to see if I have a boost leak somewhere, that isn't obvious that I haven't found yet, that is actually causing my knock values instead of the other way around.
Thanks for any help or troubleshooting direction.
M
I have attached 3 short/simple logs for review. My basic question for the gurus is:
If knock is detected, in this case 9 from 0, does the ECU bleed off boost as a precaution or does it only impact timing?
I see in my logs that I go from 0 to 9 counts of knock instantly, and it stays there. I don't here any in the car. I see that when this happens the boost is killed off. So is that ECU action or does that indicate a boost leak?
I am trying to see if I have a boost leak somewhere, that isn't obvious that I haven't found yet, that is actually causing my knock values instead of the other way around.
Thanks for any help or troubleshooting direction.
M
Last edited by fireroasted; Sep 18, 2010 at 05:47 PM. Reason: adding attachment.....duh
#2
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Im not so sure "knock counts" is being used/logged correctly. The mut 3 does not pull "knock count" data from the ecu. It reads "knock CA" OR knock retard crank angle
Im interested to see if evoscan has been incorrectly set up and the reading everyone believes is "knock counts" is actually degrees of ignition retard, anyone able to shed light on this??
Im interested to see if evoscan has been incorrectly set up and the reading everyone believes is "knock counts" is actually degrees of ignition retard, anyone able to shed light on this??
#3
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I am working on a problem I am having with a CEL posting P0325 continuously. It happen during a track day at Fontana. I have posted in advanced, but this is NOT a cross post; this is a very pointed ECUFlash troubleshooting question. Since I am trying to log to figure out if the answer to my problem is in the log data.
I have attached 3 short/simple logs for review. My basic question for the gurus is:
If knock is detected, in this case 9 from 0, does the ECU bleed off boost as a precaution or does it only impact timing?
I see in my logs that I go from 0 to 9 counts of knock instantly, and it stays there. I don't here any in the car. I see that when this happens the boost is killed off. So is that ECU action or does that indicate a boost leak?
I am trying to see if I have a boost leak somewhere, that isn't obvious that I haven't found yet, that is actually causing my knock values instead of the other way around.
Thanks for any help or troubleshooting direction.
M
I have attached 3 short/simple logs for review. My basic question for the gurus is:
If knock is detected, in this case 9 from 0, does the ECU bleed off boost as a precaution or does it only impact timing?
I see in my logs that I go from 0 to 9 counts of knock instantly, and it stays there. I don't here any in the car. I see that when this happens the boost is killed off. So is that ECU action or does that indicate a boost leak?
I am trying to see if I have a boost leak somewhere, that isn't obvious that I haven't found yet, that is actually causing my knock values instead of the other way around.
Thanks for any help or troubleshooting direction.
M
Im not so sure "knock counts" is being used/logged correctly. The mut 3 does not pull "knock count" data from the ecu. It reads "knock CA" OR knock retard crank angle
Im interested to see if evoscan has been incorrectly set up and the reading everyone believes is "knock counts" is actually degrees of ignition retard, anyone able to shed light on this??
Im interested to see if evoscan has been incorrectly set up and the reading everyone believes is "knock counts" is actually degrees of ignition retard, anyone able to shed light on this??
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#10
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Are you talking about the Evo 10 or the Evo 8/9?
Just FYI this is the Evo 1-9 section, so it has to do with the 8-9. There are actually a couple pretty good threads on knock detection in the 8-9 ECU in this area, do a search and read away.
The Evo 10, as I think you are presenting, is slightly different. There however is knock sum as well in that ECU.
- Bryan
#14
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You know, the term "knock sum" is slightly misleading. Being a "sum" it could lead somebody unfamiliar with the term to think it is a summation of the knock events? Maybe that is what he is saying, which in that regard, no, there is not a "summation of knock events" channel. Although, "octane" would be a moving average of sorts.
#15
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BTW Bryan, it is ~1/3 deg per knock count. Its just that the ignition timing MUT we have been logging all these years doesn't have the resolution to see ~1/3 deg increments.