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what's up with the knock sensor?

481 Views 2 Replies 3 Participants Last post by  Trav
How the hell does this thing work? Does it retard timing under load? I thought it just retarded the timing when it got knock, but the other day I noticed it had a vacuum hookup.
When I started messing with the cam gear and ignition timing, I was getting a LOT of ping at like 3k rpms under full load. The knock sensor is torqued to the correct position and correctly oriented. The wire insulation is frayed in some spots, but other than that it LOOKS okay. Seems to me like it shouldn't ping at all, it should just have less and less power if I advance the timing too much.
Okay, so maybe I don't really have a specific question but I'm just looking to find out how it works.
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Re: what's up with the knock sensor? (rocco2nr)

Its detects knock and retards timing accordingly. 15ft lbs if I rember correctly, of torque that is.
Re: what's up with the knock sensor? (rocco2nr)

You should be hearing some pinging prior to retardation. Yes, the vacuum line to the KCU is for load.
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