KNOCK UPDATE …now with a CEL!! :)
Discussion
(re: www.pistonheads.com/gassing/topic.asp?t=146290)
I swapped out my #3 chip a few days ago for the stock code (1994 S4) and I have been noticing less knocks, but…
1) they are still there
2) I think that they occur less only because they seem to happen on boost which is now much less often and at much higher RPMs then with chip number 3.
I took a 3 hour drive today (from Atlanta to Columbia to see my girl) hoping that it would help shake out the issues. Several knocks (10-12) occurred during the trip (all while flooring it) and I’ve attached a short log so you can see a couple of them ..the good parts are already highlighted.
(LOG: www.karmavore.net/jane/tocae1.zip)
What’s also interesting is that as I neared my destination I suddenly felt a stutter followed by the CEL. No knocks occurred during the time, but the code I received was code 42: “ELECTRONIC SPARK TIMING (EST) CIRCUIT”.
..now it sure seems like these two issues could be related, but the fact that no knocks occurred when the error was thrown makes me suspicious.
My theory, based on this log and others, is that the knock is occurring do to a lean condition. Check out the O2 voltage and A:F ratio leading up to the knocks and tell me what you think.
As always any help is treasured,
Luke.
>>> Edited by karmavore on Sunday 9th January 06:45
I swapped out my #3 chip a few days ago for the stock code (1994 S4) and I have been noticing less knocks, but…
1) they are still there
2) I think that they occur less only because they seem to happen on boost which is now much less often and at much higher RPMs then with chip number 3.
I took a 3 hour drive today (from Atlanta to Columbia to see my girl) hoping that it would help shake out the issues. Several knocks (10-12) occurred during the trip (all while flooring it) and I’ve attached a short log so you can see a couple of them ..the good parts are already highlighted.
(LOG: www.karmavore.net/jane/tocae1.zip)
What’s also interesting is that as I neared my destination I suddenly felt a stutter followed by the CEL. No knocks occurred during the time, but the code I received was code 42: “ELECTRONIC SPARK TIMING (EST) CIRCUIT”.
..now it sure seems like these two issues could be related, but the fact that no knocks occurred when the error was thrown makes me suspicious.
My theory, based on this log and others, is that the knock is occurring do to a lean condition. Check out the O2 voltage and A:F ratio leading up to the knocks and tell me what you think.
As always any help is treasured,
Luke.
>>> Edited by karmavore on Sunday 9th January 06:45
Pay very little attention to the A:F and O2. The A:F is only the ECU guesstimation and cannot be trusted since the O2 sensor is a narrowband sensor. Besides, your theory on going lean would be wrong as lean would show a higher number here... lower means rich for A:F. The O2 sensor should hit somewhere close to .9 when at WOT and oscillate back and forth otherwise. Looks good to me.
All of your highlights do not look bad at all. Knock retard is minimal and in most cases, goes away halfway through the pull, resulting in good timing and no retard.
Chargecooler looks to be working so that shouldn't be the issue.
Injector PW and consequently injector duty cycle looks good. Plenty of fuel with a buttload of room to go.
BLM looks good, never goes over 128 (over is a lean condition, under is a rich condition and even at 128 is ideal, ECM-wise), which is a good thing but something you should not see since the injectors are barely taxed as it is.
Coolant temp looks to be somewhat low. Did you put in a lower rated thermostat? Shouldn't have a bearing I don't think, just an observation.
Nothing really jumps out at me with that log and it looks pretty good. Most knocks here and there never bothered me, especially with good paremeters everywhere else, ie timing, retard... I'll go over it again in the morning since it is late and I am tired. Hopefully Dermot O'Hare will see the post and take a look. He is good at reading these logs and finding things.
As for your code 42...
Circuit Description
When the system is running on the Ignition Module, that is, no voltage on the by-pass line, the Ignition Module grounds the EST signal. The ECM expects to see no voltage on the EST line during this condition. If it sees a voltage, it sets Code 42 and will not go into the EST mode.
When the rpm for EST is reached (about 400 rpm), and by-pass voltage applied, the EST should no longer be grounded in the ignition module so the EST voltage should be varying.
If the by-pass line is open or grounded, the ignition module will not switch to EST mode, so the EST voltage will be low and Code 42 will be set.
If the EST line is grounded, the ignition module will switch to EST, but because the line is grounded there will be no EST signal. A Code 42 will be set.
Problem Description:
Code 42 is set when:
EST line open or grounded.
By-pass line open or grounded.
An improperly seated PROM can cause it. Check yours. Reset it and see if it comes back regardless. I think it throw you into "limp-home-mode". Who soldered the holder into the ECM? Maybe check that as well?
>> Edited by njgsx96 on Sunday 9th January 07:28
All of your highlights do not look bad at all. Knock retard is minimal and in most cases, goes away halfway through the pull, resulting in good timing and no retard.
Chargecooler looks to be working so that shouldn't be the issue.
Injector PW and consequently injector duty cycle looks good. Plenty of fuel with a buttload of room to go.
BLM looks good, never goes over 128 (over is a lean condition, under is a rich condition and even at 128 is ideal, ECM-wise), which is a good thing but something you should not see since the injectors are barely taxed as it is.
Coolant temp looks to be somewhat low. Did you put in a lower rated thermostat? Shouldn't have a bearing I don't think, just an observation.
Nothing really jumps out at me with that log and it looks pretty good. Most knocks here and there never bothered me, especially with good paremeters everywhere else, ie timing, retard... I'll go over it again in the morning since it is late and I am tired. Hopefully Dermot O'Hare will see the post and take a look. He is good at reading these logs and finding things.
As for your code 42...
Circuit Description
When the system is running on the Ignition Module, that is, no voltage on the by-pass line, the Ignition Module grounds the EST signal. The ECM expects to see no voltage on the EST line during this condition. If it sees a voltage, it sets Code 42 and will not go into the EST mode.
When the rpm for EST is reached (about 400 rpm), and by-pass voltage applied, the EST should no longer be grounded in the ignition module so the EST voltage should be varying.
If the by-pass line is open or grounded, the ignition module will not switch to EST mode, so the EST voltage will be low and Code 42 will be set.
If the EST line is grounded, the ignition module will switch to EST, but because the line is grounded there will be no EST signal. A Code 42 will be set.
Problem Description:
Code 42 is set when:
EST line open or grounded.
By-pass line open or grounded.
An improperly seated PROM can cause it. Check yours. Reset it and see if it comes back regardless. I think it throw you into "limp-home-mode". Who soldered the holder into the ECM? Maybe check that as well?
>> Edited by njgsx96 on Sunday 9th January 07:28
Rich,
I have looked a Luke's log before. As you say there is nothing obvious in the log files that I can point him too.
He may be poor noise filtering on the ESC module in the EPROM caused by knock sensor playing up, bad earth in the ECU, poor voltage regulation, that last error he got shortly after changing the EPROM would point me in the direction of a bad connection to or in the ECU.
It could be a mechanical vibration from the engine due to something moving under accelaration.
Dermot
I have looked a Luke's log before. As you say there is nothing obvious in the log files that I can point him too.
He may be poor noise filtering on the ESC module in the EPROM caused by knock sensor playing up, bad earth in the ECU, poor voltage regulation, that last error he got shortly after changing the EPROM would point me in the direction of a bad connection to or in the ECU.
It could be a mechanical vibration from the engine due to something moving under accelaration.
Dermot
Thanks guys. Really.
As a certified hypochondriac I knew Freescan was a bad idea for me. After I do some diagnostic tests I think I'll just end up following your advice and letting it be provided the car seems smooth. One day I'll hunt down the knock sensor and maybe replace it.
The only other thing is I worry that the retardation (the cars, not mine) is robbing me of performance, but since you all don't seem to think it's retarding much I guess I'm not.
BTW, what amount of retarding is a lot and what is a little? I saw it as high as 11 ..but just once.
Also, why does it sometimes retard the timing with out a knock?
Peace out,
Luke.
As a certified hypochondriac I knew Freescan was a bad idea for me. After I do some diagnostic tests I think I'll just end up following your advice and letting it be provided the car seems smooth. One day I'll hunt down the knock sensor and maybe replace it.
The only other thing is I worry that the retardation (the cars, not mine) is robbing me of performance, but since you all don't seem to think it's retarding much I guess I'm not.
BTW, what amount of retarding is a lot and what is a little? I saw it as high as 11 ..but just once.
Also, why does it sometimes retard the timing with out a knock?
Peace out,
Luke.
karmavore said:
As a certified hypochondriac I knew Freescan was a bad idea for me.
HAHAHA I am thinking the same thing. once you get to know the car, learn a little bit more in general, you'll get over it. Nothing wrong with caring too much. Everyone goes through it.
karmavore said:
After I do some diagnostic tests I think I'll just end up following your advice and letting it be provided the car seems smooth. One day I'll hunt down the knock sensor and maybe replace it.
Sounds good to me. if you really want more performance, I do highly recommend chip #5. For 99% of all people wanting more, this chip seriously does the trick. Also, no need to hunt down the knock sensor. Pic is courtesy of Sanj, I hope he doesn't mind...
www.databurstpc.com/data/sensors%20labelled.jpg
karmavore said:
The only other thing is I worry that the retardation (the cars, not mine) is robbing me of performance, but since you all don't seem to think it's retarding much I guess I'm not.
No performance is being robbed. Could just be mystique. you hear Lotus you think supercar. And while it is, in actuality, 264HP or the 300HP the S4s comes with is not a lot. The Lotus is quick, but by no means is it the end all of performance. Of course, my view can be slightly jaded as my daily driver for the past 4 years has been a 425HP Eagle Talon and that feels slow to me so now everything does. Anyway, from your logs, car looks good. I have found that the Lotus doesn't "feel" as fast as it really is. It is aquick car though, you may just be expecting too much, especially going from an upgraded chip back to stock.
karmavore said:
BTW, what amount of retarding is a lot and what is a little? I saw it as high as 11 ..but just once.
Also, why does it sometimes retard the timing with out a knock?
Wrong value. Knock Count is just a running count of how often the knock sensor senses something. Knock retard is how many degrees of timing is being pulled, from either a knock, or a lean/rich condition sensed, etc. I think anything more than 1-2 degrees pulled is something too look at but not worry. over that, start checking things. Overall, you should see a nice steady increase in spark advance when at WOT, and it should eventually reach around 18-19 by the top of the gear.
>> Edited by njgsx96 on Monday 10th January 02:45
njgsx96 said:
Wrong value. Knock Count is just a running count of how often the knock sensor senses something. Knock retard is how many degrees of timing is being pulled, from either a knock, or a lean/rich condition sensed, etc. I think anything more than 1-2 degrees pulled is something too look at but not worry. over that, start checking things. Overall, you should see a nice steady increase in spark advance when at WOT, and it should eventually reach around 18-19 by the top of the gear.
If you look at this log (http:\www.karmavore.netjanegas.csv) from yesterday you'll see that there was a 11.2 degree retard with no corresponding knock. Seems high, but rare too.
Also, do you think my BatV is low? It seems to be between the high 12s to low 13s. Is the a measure of the batteries health or really the alternators? Could it be low because the lights and stereo where on?
Luke.
>> Edited by karmavore on Monday 10th January 03:02
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