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MethOD

Knock sensor recommendation for Toyota 3SGTE

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I had been utilizing the factory knock sensor with my Toyota Gen4 3SGTE.  It seemed to work ok with the Link.  However, I accidentally broke it while working on the engine so I need to replace it.  Just wondering if I should get another factory sensor or if an aftermarket sensor would work better in some way. 

I imagine if I swapped to a different sensor I'd have to re-tune the knock target table and knock setup values, which would be a bit of a pain.  So I would only want to switch to a different sensor if there was a tangible benefit.

Thanks in advance

 

 

 

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If the factory sensor was giving an acceptable range of knock level numbers then there is probably no need to change to an aftermarket sensor.  You are correct in that you will need to fully retune the knock control system if you change to a different type of sensor.

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Thanks for the feedback.  I decided for now to order a good used OEM knock sensor for sake of simplicity.  However, I did try and do some research on the Bosch sensor and my takeaway is that it would provide a cleaner signal with less chance of stray noise causing false knock detection?

At any rate, I learned a new word!  Hexalobular :)

 

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I ordered what was supposed to be a good used OEM knock sensor but it looked different than the original and even with the Gain at 1 the signal was too "hot".    So I exchanged it for a new Bosch sensor and installed that and it seems to work well but I have a few questions:

First off, according to the  3sgte cylinder bore size (86mm) the knock frequency would be 6.7khz.  So should I set the Freq Channel to 4-10khz because it's a wideband sensor or 7khz because I know what frequency the knock should show up at?  I actually did some driving with each of those settings and looking at the logs I couldn't see a marked difference.

Secondly, I get spikes when lifting off the throttle.  I know this is not uncommon and it was this way even with the original knock sensor.  I've adjusted TP delta lockout to try and mitigate this but I have not had complete success.  So my question about that is -- if the ECU thinks there's knock and puts a value in the Knk Ign Trim cell for that RPM/load for that cylinder of, say -5, will it reduce and eventually return that cell to 0 as the engine passes through that load cell again and does not detect knock?  Studying the help file makes me think "yes" but I just want to confirm my understanding.

Thanks

 

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5 hours ago, MethOD said:

First off, according to the  3sgte cylinder bore size (86mm) the knock frequency would be 6.7khz.  So should I set the Freq Channel to 4-10khz because it's a wideband sensor or 7khz because I know what frequency the knock should show up at?  I actually did some driving with each of those settings and looking at the logs I couldn't see a marked difference.

Yes, 7Khz would likely be the more correct setting (should see less noise).

 

5 hours ago, MethOD said:

Secondly, I get spikes when lifting off the throttle.  I know this is not uncommon and it was this way even with the original knock sensor.  I've adjusted TP delta lockout to try and mitigate this but I have not had complete success.  So my question about that is -- if the ECU thinks there's knock and puts a value in the Knk Ign Trim cell for that RPM/load for that cylinder of, say -5, will it reduce and eventually return that cell to 0 as the engine passes through that load cell again and does not detect knock?  Studying the help file makes me think "yes" but I just want to confirm my understanding.

Normally I have found the TP delta to take care of that effect ok. 

However to confirm your assumption, yes the engine must operate in that trimmed cell for the "advance delay" time period without any knock detected, then the ecu will start removing that trim at the "advance rate" specified.

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Thank you for your response.  I'll try to go a little lower with the TP delta lockout setting.

Regarding the frequency setting, I was studying the help file some more and came across this where it actually suggests 6khz for 3SGTE and the Bosch sensor so now I'm confused again :)    Will either the 6 or 7 kHz setting look in a range  around that frequency that will include 6.7kHz?

image.png.2ffc263ae5e91fdc42a9fdb4aa33dbb1.png

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I wanted to report back and let you know that I think this new knock sensor is working out well with the frequency set at 7kHz.  It seems to be giving me a clean signal without a lot of extraneous noise during non-transient conditions

Regarding the TP Delta lockout setting.  I graphed the TP Delta alongside the knock sensor output and I saw the false knock occurring when I'd let off the throttle with TP delta values just over 1%.   So that means I'd have to set the TP Delta lockout to 1% (right?).  Is that a typical value for that setting? 

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