adjust the knock censor..
Racer
Joined: Aug 2002
Posts: 386
Likes: 0
From: Lancaster Lancashire
Re: adjust the knock censor.. (devilfish)
I believe one way to de-sesitise the knock sensor is to use Teflon (PTFE) thread tape on the threads when screwing it into the block, however I have no personal experience of this.
Maybe someone else can comment?? :D :steering:
[Modified by Davemc1963-87conv, 10:33 AM 6/23/2003]
Maybe someone else can comment?? :D :steering:
[Modified by Davemc1963-87conv, 10:33 AM 6/23/2003]
Thread Starter
Melting Slicks
Joined: Oct 2000
Posts: 3,010
Likes: 1
From: Sweden/Stockholm
Re: adjust the knock censor.. (Aaron's 87)
well im also getting knock counts @ 1500 rpm with 0% throttle. That's should be valvetrain noise. Im are also losing 6 degrees of timing due to this. My knock counts are also linear and don't change under load.
A sure sign of mechanical noise.
A sure sign of mechanical noise.
Instructor
Joined: Dec 2001
Posts: 151
Likes: 0
From: Mobile al
Re: adjust the knock censor.. (devilfish)
Try this page and look at the Knock circuit he has used.
Never tried it, no false knock here, but it sounds good on paper
http://www.charm.net/~mchaney/f-tech.htm
If you do it let us know how it works out...
Never tried it, no false knock here, but it sounds good on paper
http://www.charm.net/~mchaney/f-tech.htm
If you do it let us know how it works out...
Safety Car
Joined: May 1999
Posts: 3,651
Likes: 5
From: Atlantis
Cruise-In I Veteran
Re: adjust the knock censor.. (devilfish)
The EASIEST and the CHEAPEST way is to adjust your ECM's "Knock Attack" table and the "Knock Decay" tables on your EPROM.
The tables are set up with attack and decay rate values for different RPM ranges.
GM is pretty aggressive with their Knock Attack rate and pretty slow to bring in the Knock Decay or reduction in timing retard after knock is detected.
You can adjust the mutliplier to reduce the effect of knock sensing at the RPM you need to do this.
After you "desensitize" the knock attack rate you can go to the Knock Decay table and sensitize it to pull the knock retard back out faster after knock is detected.
I had a VERY pesky knock detection at around 2000-2200 RPM that put a big hole in my acceleration that I could feel in my SOP indicator.
After determing it wasn't real knock and only some engine noise picked up by the KS I performed the above procedure and have been smiling ever since.
I'm sure I didn't invent this procedure but no one told me about it so as always, YMMV.
[Modified by VetNutJim, 1:28 PM 8/1/2003]
The tables are set up with attack and decay rate values for different RPM ranges.
GM is pretty aggressive with their Knock Attack rate and pretty slow to bring in the Knock Decay or reduction in timing retard after knock is detected.
You can adjust the mutliplier to reduce the effect of knock sensing at the RPM you need to do this.
After you "desensitize" the knock attack rate you can go to the Knock Decay table and sensitize it to pull the knock retard back out faster after knock is detected.
I had a VERY pesky knock detection at around 2000-2200 RPM that put a big hole in my acceleration that I could feel in my SOP indicator.
After determing it wasn't real knock and only some engine noise picked up by the KS I performed the above procedure and have been smiling ever since.
I'm sure I didn't invent this procedure but no one told me about it so as always, YMMV.
[Modified by VetNutJim, 1:28 PM 8/1/2003]
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Melting Slicks
Joined: Mar 2003
Posts: 2,472
Likes: 0
From: Toronto ONTARIO
Re: adjust the knock censor.. (VetNutJim)
The EASIEST and the CHEAPEST way is to adjust your ECM's "Knock Attack" table and the "Knock Decay" tables on your EPROM.
The tables are set up with attack and decay rate values for different RPM ranges.
GM is pretty aggressive with their Knock Attack rate and pretty slow to bring in the Knock Decay or reduction in timing retard after knock is detected.
You can adjust the mutliplier to reduce the effect of knock sensing at the RPM you need to do this.
After you "desensitize" the knock attack rate you can go to the Knock Decay table and sensitize it to pull the knock retard back out faster after knock is detected.
I had a VERY pesky knock detection at around 2000-2200 RPM that put a big hole in my acceleration that I could feel in my SOP indicator.
After determing it wasn't real knock and only some engine noise picked up by the KS I performed the above procedure and have been smiling ever since.
I'm sure I didn't invent this procedure but no one told me about it so as always, YMMV.
[Modified by VetNutJim, 1:28 PM 8/1/2003]
The tables are set up with attack and decay rate values for different RPM ranges.
GM is pretty aggressive with their Knock Attack rate and pretty slow to bring in the Knock Decay or reduction in timing retard after knock is detected.
You can adjust the mutliplier to reduce the effect of knock sensing at the RPM you need to do this.
After you "desensitize" the knock attack rate you can go to the Knock Decay table and sensitize it to pull the knock retard back out faster after knock is detected.
I had a VERY pesky knock detection at around 2000-2200 RPM that put a big hole in my acceleration that I could feel in my SOP indicator.
After determing it wasn't real knock and only some engine noise picked up by the KS I performed the above procedure and have been smiling ever since.
I'm sure I didn't invent this procedure but no one told me about it so as always, YMMV.
[Modified by VetNutJim, 1:28 PM 8/1/2003]