For the Past 9 months I haven't had much problems with my Knock Sensor. It would go off on the Highway ONLY. Not when i floor it on the street or anything. Just when i get on it when on the Freeway. And that would only happen sometimes. Anyway, My car is Turboed now and I haven't had a problem with the knock sensor for the first 3 weeks of boosting(except on the Freeway). Last night, I went out driving with some friends and it hasn't stopped going off since then. Has anyone got any ideas what is going on... I do have a block guard in there, can those move around causing vibration or move downward on the block or something? I also have Forged Pistons, which i have heard causes chattering. I am just getting worried. The CEL will just go off when i am driving normal. could it be just a loose wire?

Fuel:
550 cc's
Vafc Hack running -40
intank fuel pump
FPR set at 40psi
Fuel rail

Thanks- Corey


[Modified by 95c1v1cs1, 3:18 PM 4/8/2003]

 

I know it isn't the conection to the ECU.

Anyone??

What causes teh knock sensor to go off. I think i have heard vibration... Is this True?

 

Can anyone give me their thoughts on this?

 

ok, Wiring is good. Air/Fuel is decent at this time. It is no different than before when it wasn't having this prob. I was under my car and I noticed hearing something rattling pretty good at a certain rpm from the underdrive pulley area. It almost sounded like something was loose. Can something rattleing on the block create the knock sensor to go off.

Thanks

 

It's possible that somethign loose or the forged pistons could do it. It could also be a bad knock sensor. Even when i hear detonation and my CE light does not come on. I assume this is a p72....this being the case you recu could also be faulty.

 

The knock sensor is more trouble then helpful, disable that sucker!

 

Ok, I am a complete retard and i am going to get flamed for this BIG TIME, But when i timed my car I got the advanced and retard thing backwards. So really my car was advanced like 5 degrees. I'm pretty sure that was the problem. Is my block ok... is it possible that i damaged my block, maybe the cylinder walls or something? Please post possible damages that I could of done to my block.

Thanks

 

I am still having the problem with the knock sensor. It is going off on a regular basis. Does anyone have any ideas what the problem could be??

 

Ditch the KS.

Got an o-scope to read KS output? I'm betting it is bad.

 

how did you know your knock sensor is going off?

 

hondata p28
the answer to all your problems

 

Yes, lets drop a bunch of money on a Hondata when a simple resistor will suffice if the ECU is good. KISS.

Hondata

Wasting money due to ignorance

 

What are you using to monitor your Fuel....I hope its a wideband.

Bottoz

 

He already has hondata on the way. Please help him out!!

 

Well, with the AEM you can view 'knock raw' voltage, and log it. Can you do that with a Hondata? Then he could see when it is occuring. If the Hondata has a configurable knock table, then that should be adjusted after a baseline pull. Here is how you do it wht the AEM EMS:

Identify which cylinders correspond to each knock input.
Identify the knock signal threshold above which is real knock.
Define the rate of additional fuel to be added for knock.
Set a maximum amount of fuel to be added for knock.
Define the rate that it will be removed after the knock is gone.
Define the rate of spark retard to be added for knock.
Set a maximum amount of ignition retard for knock.
Define the rate of spark advance back to normal values after the knock is gone.
Activate the knock system.


Bottoz

 

In a Honda ECU based application (OEM, or Hondata) then the KS is a waste of time. It is for monitoring spark knock at highway cruise in an effort to control combustion temps and NOx gas production. It is not used as a safety device, it is used as an emissions one. The Honda ECU ignores it at WOT and at over 5000 rpms - it's not doing anything where/when you need it. I've never understood people's desire for it (in the stock configuration).

For the gentleman in question, with a stock ECU or Hondata on the way, ditch the thing. Hondata will enable you to get rid of the KS, and a simple resistor across the KS ECU pins will disable it as far as the existing ECU is concerned.

As far as the AEM's capability... whoa. I'm curious as to how it implements DSP, as different KS builds generate different frequencies and different engines generate different frequencies which mean you have to filter the KS output with an eye to your setup... kinda hard to do with a generic standalone. You could definitely catch some hard detonation, yes, but I'd imagine the KS would be oversensitive if you had it tuned to detect mild pinging... it'd pick up road noise, engine revving, etc.

 

J. Davis- I was told to do a slow pull, from idle to redline with as little throttle as possible, and Log the Knock Raw Voltage. That will tell you how much 'noise' you engine makes normally. Then, to set up Knock Table values, increase the Knock Raw Voltage by 10-20% across the RPM band. You can scale how much retard you want per knock instance. For example, if you Knock goes .1v over the threashold it won't really do much.....but if it goes .5v or 1.0v over then the knock table will retard your timinmg. My base map retarded timing 2.19º/volt over the knock threashold.

Example- 4800 RPM knock raw voltage may = 1.3Volts....no ignition retard
But if at 4800 RPM knock raw voltage = 2.3Volts, then timing is retarted 2.19º.

I hope that made sence. AEM

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Ditch the KS.

Got an o-scope to read KS output? I'm betting it is bad.</TD></TR></TABLE>

Whats an o-scope? I am seriously considering the KS is bad.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by _Endless_ &raquo;</TD></TR><TR><TD CLASS="quote">how did you know your knock sensor is going off?</TD></TR></TABLE>

Pulled the code

 

I actually sent my P28 out to Hondata yesterday to get chipped. I am just worried there might be something wrong with the engine just b/c i didn't have a problem with it bofore and now i do. I can't wait to get my hondata.

 

I have been playing with my fuel and turned it basically pig rich and I have set the ignition timing to 6 degrees retarded from stock and still get the KS. I am getting the idea that the knock sensor is shot from the abuse it to when I advanced my timing One person i talked to mentioned my valves could could be causing the KS to go off... Is this true?

 

Bottoz, that does make some sense. I have an AEM I can play with about 4 hours from here (lol) so I don't have much opportunity to play with one. Thanks for the heads up.

 

Has anyone heard of the clicking valves to set off knock sensor?