LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

knock problem...

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Old Jul 19, 2004 | 09:08 AM
  #1  
blkchevyz's Avatar
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knock problem...

i just did a cam swap, and i'm getting alot of knock retard... but its not consistint. i drove for a good 1/2 hour without getting any at all, highway and city driving.

but other times i get it even at idle, i was seeing 5 degrees(thats all i allow the computer to take out at low rpms)


Last edited by blkchevyz; Jul 19, 2004 at 10:39 AM.
Old Jul 19, 2004 | 11:32 AM
  #2  
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Re: knock problem...

Yeah, I have some of the same problems. Mine was pulling 5 degrees at idle when I had a loose rocker arm. I'll probably just end up having all of my knock tables programmed out.
Old Jul 19, 2004 | 12:00 PM
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Re: knock problem...

if it was all the time i would but since its speratic i rather not.
Old Jul 19, 2004 | 04:17 PM
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Re: knock problem...

Do a search and get the resistor part#from Radio Shack and install it in line to the CPU.
False knock from exhaust or RR's will kill performance.
Old Jul 19, 2004 | 04:30 PM
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Re: knock problem...

Originally Posted by 1racerdude
Do a search and get the resistor part#from Radio Shack and install it in line to the CPU.
False knock from exhaust or RR's will kill performance.
does this disable the knock sensor?
Old Jul 19, 2004 | 04:34 PM
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Re: knock problem...

This might be a stupid question, but do you have an LT4 knock module?
Old Jul 19, 2004 | 04:39 PM
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Re: knock problem...

yeah i have the lt4 knock modual. sorry i thought i had that in my signature.
Old Jul 19, 2004 | 04:45 PM
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Re: knock problem...

Yes,It tricks the CPU into thinking the sender is connected and there is no knock in the engine whatever it might be picking up for knock.
Had the same problem after headers and that fixed it.I had the LT-4 module too.
Old Jul 19, 2004 | 07:05 PM
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Re: knock problem...

Originally Posted by 1racerdude
Yes,It tricks the CPU into thinking the sender is connected and there is no knock in the engine whatever it might be picking up for knock.
Had the same problem after headers and that fixed it.I had the LT-4 module too.
so would it not be able to detect knock from a cheaper grade gas or something pinging if you did this?
if so, that could be detrimental to your engine, so i wouldnt be recommending this to anybody who fills on something other than premium
Old Jul 19, 2004 | 07:16 PM
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Re: knock problem...

If you want performance,what other grade of gas ya gonna use?????
Old Jul 19, 2004 | 07:18 PM
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Re: knock problem...

Originally Posted by 1racerdude
Do a search and get the resistor part#from Radio Shack and install it in line to the CPU.
False knock from exhaust or RR's will kill performance.
tell me about it i have 15 degrees of false knock at wot,and my xe 230/236 cam on the dyno stops pulling at 5900rpm, still dynoed 386rwhp,so iam hoping for 400 or close to it when i take out the knock.should i have pcmforless just desensitize my knockl module or what?
Old Jul 19, 2004 | 07:31 PM
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Re: knock problem...

You could,but the resistor does it and you can always enable it again by taking the resistor out.
Old Jul 19, 2004 | 07:39 PM
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Re: knock problem...

Is there any way you could rig up some sort of a switch that would allow you to switch the knock sensor on and off? Like when you went to the track you could turn it off, but during daily driving have it on?

I guess the resistor would do that, but depending on underhood location could be a pain in the ***.
Old Jul 19, 2004 | 07:58 PM
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Re: knock problem...

Yes,cut the right wire and mount a two position switch on the dash.One side with the resistor one side without.Depending on where the switch is,that is what you are running.Just running 4 wires inside and hooking them up correctly.
Old Jul 19, 2004 | 08:04 PM
  #15  
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Re: knock problem...

Forgot to mention,if you drive it right during the week,it isn't going to matter about a bad load of gas because I'm sure you aren't going to fill with 87 Octane.Most of the problems are from false knock and nothing to do with gas and you probably are not tuned on the ragged edge.



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