PDA

View Full Version : i hear detonation but can't see it



ASSAMI
February 5th, 2007, 01:11 AM
Hello guys ,

How can I know if the knock sensors are lazy ??

I have this, Chevy CAMARO that I'm trying to tune. Everything is fine on the DYNO but when I went out for a road test it hit me !!!

The dam engine is detonating like hell …. I can hear it so clearly when I put the windows up ( low RPM part throttle – high RPM WOT )!!!!
The problem is I can not see anything on my scanner it shows 0° of knock even if I melting the engine !!!!:Eyecrazy:


Please look at the file and tell me if I'm doing anything wrong ?


Thanks for your help guys

ASSAMI
February 5th, 2007, 04:17 AM
Here is the scam for that same vehicle with the same tune .
As you can see there is not a single detonation that was deducted !!!

As I said you can clearly hear that detonation under load with the windows closed .

I thought for a moment that it was filed detonation . I added 4 liters( one gallon ) of C16 to a half full tank and the car was running like crazy with not a single det that I've heard . That makes what I was hearing for sure is detonation before the C16


Hope this helps you to help me :)

joecar
February 5th, 2007, 05:36 AM
ASSAMI,

Several things from looking at your files:
- looks like there is too much spark advance for a 2002 F-body;
- IAT settles to 38C/100F after car is going, so the ambient air is hot (where are you located...?);
- LTFT's are zero throughout, running OL, do you know the AFR...?
- MAP sensor hits 95 kPa at WOT, does this match your elevation...?
- Injector duty cycle hits 90%, it's getting close.

The knock sensors may not hear all knock, and they do degrade over time;
also, changing engine internals may move the knock resonant frequency.

RonC
February 5th, 2007, 02:03 PM
It looks like several changes have been made to the Knock and the Knock-Software settings. You might trying resetting to stock and start over to see if it knocks with those settings. I think some of your spark curves could use a little reworking and it would improve driveability after you find your no-knock problem.

johnsZ06
February 6th, 2007, 06:55 AM
Check out the TPS. It stays on "0" until he's up to 85 mph!

Of course, that doesn't have anything to do with your problem but a few PIDs are based on throttle position.

joecar
February 6th, 2007, 08:13 AM
Check out the TPS. It stays on "0" until he's up to 85 mph!

Of course, that doesn't have anything to do with your problem but a few PIDs are based on throttle position.I didn't see that one... yes, that's very important.

johnsZ06
February 6th, 2007, 01:54 PM
You should pull some of the timing as well. No need to go over 40 degrees on an LS1 at cruise.

ASSAMI
February 6th, 2007, 08:57 PM
joecar:

Several things from looking at your files:

- looks like there is too much spark advance for a 2002 F-body; (( I JUST WANTED YOU PEPOLE TO SEE THAT THE KNOCK IS NOT HEARING ANYTHING IT IS DOWN 5D NOW))

- IAT settles to 38C/100F after car is going, so the ambient air is hot (where are you located...? (( SAUDI ARABIA THE OUTSAID TIMP IS 29c ))

- LTFT's are zero throughout, running OL, do you know the AFR...? (( ON THE DYNO IS 12.8 AT MAX TORQ AND 13 UP END ))

- MAP sensor hits 95 kPa at WOT, does this match your elevation...? (( SEA LEVEL ))

- Injector duty cycle hits 90%, it's getting close. (( YES THANKS ))


The knock sensors may not hear all knock, and they do degrade over time;(( CAN YOU EXPLAIN ))

Also, changing engine internals may move the knock resonant frequency.(( THE CAR CAME WITH AFR 64cc AND A SMALL CAM. DOING 362whp ))

ASSAMI
February 6th, 2007, 08:58 PM
It looks like several changes have been made to the Knock and the Knock-Software settings. You might trying resetting to stock and start over to see if it knocks with those settings. I think some of your spark curves could use a little reworking and it would improve driveability after you find your no-knock problem.

I DID…. ITS ALMOST THE SAME L

ASSAMI
February 6th, 2007, 09:06 PM
Check out the TPS. It stays on "0" until he's up to 85 mph!

Of course, that doesn't have anything to do with your problem but a few PIDs are based on throttle position.


CANT SEE IT ? WHAT ARE U TALKING ABOUT !!:help2:

Biggsy
February 6th, 2007, 09:25 PM
Sorry, I cant see it either:Eyecrazy:

Dave.

joecar
February 6th, 2007, 11:43 PM
joecar:

Several things from looking at your files:

- looks like there is too much spark advance for a 2002 F-body; (( I JUST WANTED YOU PEPOLE TO SEE THAT THE KNOCK IS NOT HEARING ANYTHING IT IS DOWN 5D NOW))

- IAT settles to 38C/100F after car is going, so the ambient air is hot (where are you located...? (( SAUDI ARABIA THE OUTSAID TIMP IS 29c ))

- LTFT's are zero throughout, running OL, do you know the AFR...? (( ON THE DYNO IS 12.8 AT MAX TORQ AND 13 UP END ))

- MAP sensor hits 95 kPa at WOT, does this match your elevation...? (( SEA LEVEL ))

- Injector duty cycle hits 90%, it's getting close. (( YES THANKS ))


The knock sensors may not hear all knock, and they do degrade over time;(( CAN YOU EXPLAIN ))

Also, changing engine internals may move the knock resonant frequency.(( THE CAR CAME WITH AFR 64cc AND A SMALL CAM. DOING 362whp ))At sea level you would expect 97+ kPa... I suppose 95 kPa is close, but...

They can wear out over time, they can get rusted up due to condensation being trapped under the intake manifold, they can simply fail, or their wiring may be broken; you may or may not get a DTC.

johnsZ06
February 7th, 2007, 02:15 AM
CANT SEE IT ? WHAT ARE U TALKING ABOUT !!:help2:


Disregard.

I guess I was looking at decel. I have ETC so I'm not use to seeing 0 TPS readings. And I very seldom have my foot off the gas for extended periods of time so it looked rather odd to me.

Sorry bout dat!

Biggsy
February 7th, 2007, 03:30 AM
Disregard.

I guess I was looking at decel. I have ETC so I'm not use to seeing 0 TPS readings. And I very seldom have my foot off the gas for extended periods of time so it looked rather odd to me.

Sorry bout dat!

ahhh, thought I was going nuts there for a while!:D

Dave.

joecar
February 7th, 2007, 04:13 AM
Looking at his log again, TPS is good.

http://img117.imageshack.us/img117/1897/pic1cw0.png

ASSAMI
February 7th, 2007, 09:23 PM
THANKS ALL,

But tell now youi have locked at my tune and did not answer my Q !!!

How can I know if the knock sensors are lazy ??
i hear detonation but can't see it !!

Biggsy
February 7th, 2007, 11:01 PM
Install new ones and if it makes no difference, the original ones are not lazy!

Dave.

johnsZ06
February 8th, 2007, 02:27 AM
I don't think knock sensors are the end all to knock retard. I sometimes hear pinging in my engine but it doesn't register while scanning. I think it's the nature of the beast.

If you're worried about it, pull some timing, a degree at a time, until you can't hear it and call it a day.

Just my .02. :D

joecar
February 8th, 2007, 05:19 AM
How can I know if the knock sensors are lazy ?? http://www.gearchatter.com/viewtopic9363.php

ASSAMI
February 9th, 2007, 11:44 PM
Install new ones and if it makes no difference, the original ones are not lazy!

Dave.

:eek:

ASSAMI
February 9th, 2007, 11:56 PM
if the KS is dropped it must be replaced.

interesting.