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Trying to get Knock information straight

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94EclipseGST

15+ Year Contributor
334
0
Sep 1, 2003
Des Plaines, Illinois
I still see some knock at part-throttle, even thought I recently made great breakthroughs in my tuning finally. I'm still getting up to 15 counts of knock every now and again when I'm not even boosting.

So, my question is, is this knock that I should worry about? Should you worry about knock in any given situation, or does it matter only under boost conditions.

Sorry about the rookie question.

Steve
 
I have a feeling everyones gonna say "phantom knock, don't worry about it" but you should do a good check up on everything. Check for boost leaks, exhaust leaks, fouled plugs, all that good stuff. Most of the time it can't be "tuned" out with more fuel. Seems like most of the fixes I'm reading these days are all boost leaks being found. Good luck with it.

edit: BTW, real knock is going to be bad in any circumstances but under WOT/boost/high RPM conditions is where it's going to be the most destructive.
 
Yes, this is where it gets aggravating. I have done all the basic maintenance, checked timing again, checked for boost leaks (found the wastegate was not closed all the way, and that is what initially changed things for the better). I can't really think of anything else except maybe heat soak. I have all the mods in stage one and two, but did not put on the FMIC yet. I've been procrastinating with doing pipes. I guess I'll have to do that now and see if that clears things up.
 
I had the same symptoms you were having, lots of partial throttle knock, and richening up my low throttle settings on my safc pretty much cured ALL of it...maybe try that? Did you replace your knock sensor with a new one yet?
 
If I richen up the settings on the MAFT, I get knock and rich studder. I haven't thought about changing the knock sensor, because it doesn't really seem like it is malfunctioning.
 
Hmmm...well your knock sensor is 10 years old. Alot can happen to it during the course of 10 years. It might be worth the trouble because by replacing it you eliminate one more variable out of the equation. Trying to debug knock problems is a pain in the arse, but you do it by slowly replacing everything, tightening up all bolts, and tuning your fuel curve. Maybe you are running too rich? When I had my safc WAY too rich I noticed I would get huge amounts of knock at random times. Anyways, good luck to you, I'm sure you will figure it out, its just a matter of time (and money ;) ).
 
I had very similar symptoms to what you are describing. I was able to get low to 0 knock under boost and at WOT but I would get random patterns of knock during part-throttle cruise conditions. I replaced the knock sensor, which was obviously bad on inspection and the problem went away. Put your fingers against the back of the knock sensor, if they come back with a gooey brown substance on them your knock sensor is toast.
 
94EclipseGST said:
Where is the knock sensor located?

The knock sensor is located on the bottom rear of the intake manifold underneath a mounting bracket. It is more easily accessed if you remove the battery. You can then reach down past the throttle body with your left hand and feel along the manifold until you feel the bracket at the bottom. There is a hole in the center of the bracket with a wire attached to it, follow the wire towards the block and at the end of it will be the knock sensor.
 
***thread hijacked****

kidding...

I have a question, supposed your knock sensor is fautly and the cel throws a code. Does the computer have a standard knock value when the knock sensor isn't present?? What knock values does it use and what does it base them on??

Thanks

***thread returned****
 
Cesar said:
***thread hijacked****

kidding...

I have a question, supposed your knock sensor is fautly and the cel throws a code. Does the computer have a standard knock value when the knock sensor isn't present?? What knock values does it use and what does it base them on??

Thanks

***thread returned****

If the knock sensor fails and throws a code or is unplugged the computer will default to 9 counts of knock at all times. This is a default "safe" setting to keep timing retarded in all rpm and loading ranges. Hope this helps.
 
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