Tuning saga.. tuner said possible bad PCM?
#21
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Your VE table matches a stock LS1 F-Body, which I see you noted. I don't think that is helping at all. I know it's a MAF only tune, but if the MAF fails, the VE tables are the backup. I also think that the timing table is hurting you at mid-load. Here is a tune that was done by a very reputable tuner on my car when it was basically cam-only. Should give you an idea what the timing and VE maps should look like. This was a "safe mode" tune, so the timing is not as high as a typical tune would be.
Honestly, you should look through much of this tune for a really good idea of what should be different and what should match stock. You can get a stock F-body tune off HPT website to use for compare purposes.
Lastly, here are some simple mechanical checks: spark plugs - if they are not TR6, try a set of TR6 plugs. Is your Y pipe catted? Are you sure the cats aren't plugged? Is your PCV bypassing a lot of oil? Those three items can be the cause of detonation as well.
Honestly, you should look through much of this tune for a really good idea of what should be different and what should match stock. You can get a stock F-body tune off HPT website to use for compare purposes.
Lastly, here are some simple mechanical checks: spark plugs - if they are not TR6, try a set of TR6 plugs. Is your Y pipe catted? Are you sure the cats aren't plugged? Is your PCV bypassing a lot of oil? Those three items can be the cause of detonation as well.
Last edited by Darth_V8r; 02-09-2016 at 09:13 PM.
#22
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His tune is also set for a max KR of 4 degrees when in PE mode.
I think that's why it see 4 deg of retard all the time.
But the setting is stock.
Thanks for trying my suggestions.
You need to set the low octane table to be the same as the high octane table. You car is running on the low table, I see it at 23 degrees right before it begins knocking.
And good you went to the new scanner. It's better! I see your AFR is now much more believable. :-)
I don't see any issues with your MAP sensor. And changing your PE Pedal back to stock is worth a try. It will get better economy, but I don't think it's the issue.
Ron
I think that's why it see 4 deg of retard all the time.
But the setting is stock.
Thanks for trying my suggestions.
You need to set the low octane table to be the same as the high octane table. You car is running on the low table, I see it at 23 degrees right before it begins knocking.
And good you went to the new scanner. It's better! I see your AFR is now much more believable. :-)
I don't see any issues with your MAP sensor. And changing your PE Pedal back to stock is worth a try. It will get better economy, but I don't think it's the issue.
Ron
Last edited by RonSSNova; 02-10-2016 at 04:58 AM.
#23
Your knock sensors look like they are set up to be more sensitive vs a stock tune. Here is your knock sensor level vs RPM vs cyl:
lower numbers mean the sensors react sooner to vibration .
I suggest putting the stock knock sensor values back in and see if it improves any.
lower numbers mean the sensors react sooner to vibration .
I suggest putting the stock knock sensor values back in and see if it improves any.
Along those same lines, i hear a rattle near the muffler. I assume its the heat shield under the gas tank. Been wanting to remove that shield but just wanna confirm gas tank won't explode Do you think that small rattle could be heard all the way up there and could be reason of the KR?
#24
Honestly, you should look through much of this tune for a really good idea of what should be different and what should match stock. You can get a stock F-body tune off HPT website to use for compare purposes.
Lastly, here are some simple mechanical checks: spark plugs - if they are not TR6, try a set of TR6 plugs. Is your Y pipe catted? Are you sure the cats aren't plugged? Is your PCV bypassing a lot of oil? Those three items can be the cause of detonation as well.
Lastly, here are some simple mechanical checks: spark plugs - if they are not TR6, try a set of TR6 plugs. Is your Y pipe catted? Are you sure the cats aren't plugged? Is your PCV bypassing a lot of oil? Those three items can be the cause of detonation as well.
I will put new TR55 plugs in (sitting on shelf); you noted TR6 but i thought tr55 was the standard.
Y pipe is not catted (off road).
I have the valve cover vent holes (pass and driver sides) going to a single catch can; haven't checked it lately but i will. thanks!!!!
#25
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wow . thats crazy. i had no clue but thank you. I will definitely try that ASAP.
Along those same lines, i hear a rattle near the muffler. I assume its the heat shield under the gas tank. Been wanting to remove that shield but just wanna confirm gas tank won't explode Do you think that small rattle could be heard all the way up there and could be reason of the KR?
Along those same lines, i hear a rattle near the muffler. I assume its the heat shield under the gas tank. Been wanting to remove that shield but just wanna confirm gas tank won't explode Do you think that small rattle could be heard all the way up there and could be reason of the KR?
One other "nuclear option" type thought. I once had a cam that was ground 9 degrees off (advanced). That caused tremendous KR issues that weren't possible to tune out completely. Have you considered verifying your cam is properly degreed in?
#27
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The other thing I would do is change the knock decay rate. Stock decay rates are ridiculously long that you cant correspond to what timing cell or rpm knock is actually occurring at. I usually set my stuff to .25 so as soon as knock stops, it doesn't pull timing any longer.
#28
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The other thing I would do is change the knock decay rate. Stock decay rates are ridiculously long that you cant correspond to what timing cell or rpm knock is actually occurring at. I usually set my stuff to .25 so as soon as knock stops, it doesn't pull timing any longer.
Also just read that if you download the latest 3.0.18 as of today, you will get double the data speed. :-)
Last edited by RonSSNova; 02-10-2016 at 01:26 PM.
#29
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hi again - i do have a stock 98 camaro tune off the repository for comparison purposes.
I will put new TR55 plugs in (sitting on shelf); you noted TR6 but i thought tr55 was the standard.
Y pipe is not catted (off road).
I have the valve cover vent holes (pass and driver sides) going to a single catch can; haven't checked it lately but i will. thanks!!!!
I will put new TR55 plugs in (sitting on shelf); you noted TR6 but i thought tr55 was the standard.
Y pipe is not catted (off road).
I have the valve cover vent holes (pass and driver sides) going to a single catch can; haven't checked it lately but i will. thanks!!!!
#30
Your knock sensors look like they are set up to be more sensitive vs a stock tune. Here is your knock sensor level vs RPM vs cyl:
6 5 6 6 6 5 7 6 7 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 9 9 8 9 8 8 8 9 8 8 8 8 8 8 8 8 8
8 4 5 8 7 8 7 7 6 7 7 8 7 7 8 8 8 8 8 8 8
7 4 5 7 7 6 7 8 7 7 6 6 7 7 8 8 8 8 8 8 8
6 4 5 6 6 8 7 6 6 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 8 6 7 7 8 6 7 7 7 7 8 8 8 8 8 8 8
8 5 5 8 7 7 7 6 7 6 6 7 7 8 8 8 8 8 8 8 8
9 4 5 9 7 6 7 8 8 6 7 7 7 7 8 8 8 8 8 8 8
Here is the stock table:
9 9 10 10 10 10 10 9 11 10 10 9 9 9 9 9 9 9 9 9 9
10 10 11 11 10 10 10 11 10 10 10 11 11 11 11 11 11 11 11 11 11
8 8 9 9 10 9 9 10 9 10 9 9 9 9 9 9 9 9 9 9 9
8 8 9 9 10 9 9 9 8 9 8 9 9 9 9 9 9 9 9 9 9
9 9 10 10 10 9 10 9 9 10 9 10 10 10 10 10 10 10 10 10 10
10 10 11 9 10 10 9 9 11 10 10 8 8 8 8 8 8 8 8 8 8
9 9 10 10 10 10 10 11 10 10 10 9 9 9 9 9 9 9 9 9 9
9 9 10 11 10 10 9 10 11 9 11 9 9 9 9 9 9 9 9 9 9
lower numbers mean the sensors react sooner to vibration .
I suggest putting the stock knock sensor values back in and see if it improves any.
6 5 6 6 6 5 7 6 7 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 9 9 8 9 8 8 8 9 8 8 8 8 8 8 8 8 8
8 4 5 8 7 8 7 7 6 7 7 8 7 7 8 8 8 8 8 8 8
7 4 5 7 7 6 7 8 7 7 6 6 7 7 8 8 8 8 8 8 8
6 4 5 6 6 8 7 6 6 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 8 6 7 7 8 6 7 7 7 7 8 8 8 8 8 8 8
8 5 5 8 7 7 7 6 7 6 6 7 7 8 8 8 8 8 8 8 8
9 4 5 9 7 6 7 8 8 6 7 7 7 7 8 8 8 8 8 8 8
Here is the stock table:
9 9 10 10 10 10 10 9 11 10 10 9 9 9 9 9 9 9 9 9 9
10 10 11 11 10 10 10 11 10 10 10 11 11 11 11 11 11 11 11 11 11
8 8 9 9 10 9 9 10 9 10 9 9 9 9 9 9 9 9 9 9 9
8 8 9 9 10 9 9 9 8 9 8 9 9 9 9 9 9 9 9 9 9
9 9 10 10 10 9 10 9 9 10 9 10 10 10 10 10 10 10 10 10 10
10 10 11 9 10 10 9 9 11 10 10 8 8 8 8 8 8 8 8 8 8
9 9 10 10 10 10 10 11 10 10 10 9 9 9 9 9 9 9 9 9 9
9 9 10 11 10 10 9 10 11 9 11 9 9 9 9 9 9 9 9 9 9
lower numbers mean the sensors react sooner to vibration .
I suggest putting the stock knock sensor values back in and see if it improves any.
mine which is same as stock 98 camaro i'm looking at:
6 5 6 6 6 5 7 6 7 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 9 9 8 9 8 8 8 9 8 8 8 8 8 8 8 8 8
8 4 5 8 7 8 7 7 6 7 7 8 7 7 8 8 8 8 8 8 8
7 4 5 7 7 6 7 8 7 7 6 6 7 7 8 8 8 8 8 8 8
6 4 5 6 6 8 7 6 6 6 8 8 7 8 8 8 8 8 8 8 8
9 4 5 9 8 6 7 7 8 6 7 7 7 7 8 8 8 8 8 8 8
8 5 5 8 7 7 7 6 7 6 6 7 7 8 8 8 8 8 8 8 8
9 4 5 9 7 6 7 8 8 6 7 7 7 7 8 8 8 8 8 8 8
and here is the stock 2004 z06:
11 11 11 11 11 11 11 11 11 10 10 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11
11 11 11 11 11 11 11 11 10 10 9 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 10 10 9 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 10 10 10 10 10 10 10 10 10 10 10 10 10
11 11 11 11 11 11 11 11 10 10 10 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 10 10 10 9 9 9 9 9 9 9 9 9 9
11 11 11 11 11 11 11 11 11 10 11 9 9 9 9 9 9 9 9 9 9
#31
The other thing I would do is change the knock decay rate. Stock decay rates are ridiculously long that you cant correspond to what timing cell or rpm knock is actually occurring at. I usually set my stuff to .25 so as soon as knock stops, it doesn't pull timing any longer.
0.010009765625 0.010009765625 0.012451171875 0.012451171875 0.014892578125 0.014892578125 0.015625 0.015625 0.015625 0.015625 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125
changing to .025 is doubling the value but .25 would be way too high. right?
#32
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Won't quote good on my phone. Those I posted are the stock 1999 values. If still say give it a shot. Cammed cars naturally make more noise and tend to need KS a bit less sensitive
#33
hi - i made some changes tonight. Log files are short because its friggin snowing but i'm still getting kr. Went back to the original tune and made these changes:
-lowered KR sensitivity by inputing a higher numerical value – copied from 2004 z06 (spark – knock sensors – RPM vs Cyl)
-changed PE back to stock
There is no oil in my catch can.
I still want to change my plugs (TR55 on shelf).
I will check the rattling but I really don't think that is it.
Max value of the KR in the log is less than last night. Keep in mind last nights changes to the tune were made it richer (high 11's), and low octane table was higher than the high octane table. I reversed both of those and just started with the base tune since those changes did nothing. Tonights a/f was mid 12's.
does the jagged STFT and LTFT have any significance?
-lowered KR sensitivity by inputing a higher numerical value – copied from 2004 z06 (spark – knock sensors – RPM vs Cyl)
-changed PE back to stock
There is no oil in my catch can.
I still want to change my plugs (TR55 on shelf).
I will check the rattling but I really don't think that is it.
Max value of the KR in the log is less than last night. Keep in mind last nights changes to the tune were made it richer (high 11's), and low octane table was higher than the high octane table. I reversed both of those and just started with the base tune since those changes did nothing. Tonights a/f was mid 12's.
does the jagged STFT and LTFT have any significance?
#34
TECH Senior Member
Tuning saga.. tuner said possible bad PCM?
There is a known problem with 1998 knock senors reporting a constant 4* KR... the GM Tech Bulletin says to replace both KS's and the subharness and quotes GM part numbers.
If you think this applies to your situation, check what KS's and subharness you have (are they GM or ACDelco).
If you think this applies to your situation, check what KS's and subharness you have (are they GM or ACDelco).
#35
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do you mean .25 or .025? because the stock values are closer to .025 range. See below stock tables, mine are same as stock:
0.010009765625 0.010009765625 0.012451171875 0.012451171875 0.014892578125 0.014892578125 0.015625 0.015625 0.015625 0.015625 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125
changing to .025 is doubling the value but .25 would be way too high. right?
0.010009765625 0.010009765625 0.012451171875 0.012451171875 0.014892578125 0.014892578125 0.015625 0.015625 0.015625 0.015625 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125 0.012939453125
changing to .025 is doubling the value but .25 would be way too high. right?
#37
already done:
...
Second tuner (after weeks with the car) said he had car running great. But on the next night says he says its getting 4 degrees KR and found knock sensor error code and figured that he would change the knock sensors with new ones. While doing that, he saw the knock sensor wiring harness crimped in between the transmission and the engine and said that was causing a short and triggered the error code. So he put in new harness and continued tuning. …
Second tuner (after weeks with the car) said he had car running great. But on the next night says he says its getting 4 degrees KR and found knock sensor error code and figured that he would change the knock sensors with new ones. While doing that, he saw the knock sensor wiring harness crimped in between the transmission and the engine and said that was causing a short and triggered the error code. So he put in new harness and continued tuning. …
#40
TECH Addict
I heard if you over torque them they might not work so torque to proper specs. I think i was next to you during the fall by the healey chevy in Middletown. Your car sounds good.