So how do these things work anyway?

Does it create/break a ground path when it senses vibration [knock]?

I've heard rumors that you can tune the sensitivity of the knock sensor depending on how tight it's threaded in the block. Has anybody actually experimented with this?....just a thought.

later

 

Here's a good post on it:

https://www.thirdgen.org/techbb2/sho...hreadid=101000

I'm pretty sure that it doesn't gain sensitivity the further it is threaded in.

 

as for the sensor itself i think it might have a peizoelectric transducer in it that sends a signal to the computer when a pressure wave, which is from the detonation, travleing through the steel and cast iron encounters it. Morley brough up a good point that the ecm goes through a routine to check the sensor at moderate to high loads by advancing the timing untill it detects knock, if no knock is detected, the ses light illuminates and a code 43 is stored. The ses light will go off when the engine is shut down or lnock is again encountered, Ive seen this with my low compression 350. There will be one lone solitary count at a high map value on the table where the computer perfoms the check. I ahd the ses light illuminate and a 43 set on me when i wasnt running the proper timing. too retarded.

 

Thanks for the info. Still trying to track down my intermittent code 43 problem without throwing parts at it. Thought about unpluggging the knock sensor hoping it would be disabled so I could rule it out but doesn't sound like that's an option.

everytime I use winaldl the damn thing runs mint!

 

lazylo5, do you hear any knock when the code is set? Does it set w/o the engine bogging or does it bog when it sets? It could also be a bad module or possibly alot of carbon buid up in the combustion chamber.