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more... Posted by JimBlake [Email] ![]() ![]() ![]() In Reply to: Re: maybe not???, Todd H., Mon, 19 Aug 2002 20:29:55 Members do not see ads below this line. - Help Keep This Site Online - Signup |
The knock sensor is basically a microphone, bolted to the block. The EZK box is supposed to tell the difference between normal engine vibrations vs. spark knock, based on frequency and/or timing. I'm guessing that maybe its making bogus noise which happens to sound like spark knock. Or the EZK box is getting flaky rather than the sensor. Corroded connections including grounds can make all kinds of electical noise at mv or lower levels, so maybe that's part of it.
We've got a '89 n/a so I'm just assuming that yours is about the same. It does not constantly hunt for the point of incipient knock. It has a spark advance map based on rpm & load. When it hears knocking it retards the timing by 3 degrees from the map, 5 seconds later it goes back to the map. Or if it still hears knock, it retards 3 more degrees, etc. I thought it flashed the CEL at that point, which is not really a 'failure', but its the EZK system doing its job. Other people on this board have said it only flashes when the EZK system fails. I guess I'm not really sure.
I've also read here that the orientation of the sensor bolted to the block makes a difference. I'll try to remember to look at it tonight, but I don't know if it would be the same as your year... try searching back to find that post.
(maybe more than you wanted to know?)
posted by 131.184.14...
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