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-   -   knock sensor options? (https://www.rx7club.com/rotary-car-performance-77/knock-sensor-options-158444/)

82streetracer 02-15-03 04:46 PM

knock sensor options?
 
I know of the J&S sensor that retards the leading timing.
But thats exspensive and Ive heard of it causing further problems with retarding it too far.


What about a stand alone meter that will tell me the sensors output. Is there something like that I can buy.

82streetracer 02-16-03 09:51 PM

Okay, if no meter exists...

what kind of signal does a knock sensor produce. Could I read it with a multimeter or somethige?

Brentis 02-16-03 11:01 PM

PFC shows knock on a gen 3

82streetracer 02-17-03 08:39 PM

what??? PFC?

this is on a FB with a 91 TII motor. Haltech E6k

bureau_c 02-17-03 11:18 PM

I don't think the sensor itself has any smarts...its basically a microphone (I'm not an expert here so if somebody knows differently speak up). My understanding is that the smarts to figure out what to do about it are in the ECU. The stock ECU doesn't really do too much because it isn't smart enough to differentiate knock from other noises before the knock is serious knock. I don't think the PFC does anything with it at all other than display the output of the sensor. The J&S seems to be about the most intelligent box for this, as you would expect from something designe specifically for the task.

It would be easy to put something like one of the LED bar graph AFR gauges on the output of the knock sensor. Depending on the voltage range of that output, you may not even have to modify it (the 02 sensor is between 0-1 Volt...anything else would require a minor change to the gauge circuit). However, this would be completely useless, much like the knock indication on the PFC. Sure, it will show you knock...but it will also show you half a dozen normal sounds that are indistinguishable from knock without complex computer processing.

jds

82streetracer 02-18-03 11:48 AM

shit,

Ill just go without one. I can hear engine knock on my 5.0 crown vic pretty easy.

what does rotary knock sound like
.

importboi22 02-19-03 01:05 PM


Originally posted by 82streetracer
shit,

Ill just go without one. I can hear engine knock on my 5.0 crown vic pretty easy.

what does rotary knock sound like
.

boom! bye bye motor

bureau_c 02-19-03 01:40 PM

According to the FSM, the FD ECU retards timing bit when it thinks it detects knock. I know the J&S does it a lot more effectively, plus it is (I think) adjustable. However, I seriously doubt the stock knock sensor is saving very many motors.

jds

es 02-19-03 01:56 PM

"boom! bye bye motor"

More like "CRACK!". Sort of like somebody took a hammer & smacked the top of your motor...

82streetracer 02-19-03 08:58 PM

where can i find more info on the J&S, and who sells it cheap.


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