LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Knock Sensor Circuit?

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Old Jun 22, 2011 | 06:40 AM
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Default Knock Sensor Circuit?

Guys,

Still tracing down my possible false knock and I tested the knock sensor and wire/plug. The sensor itself ohm'd out fine at 4k, however my plug is showing 4.20v with key on and according to shbox it should be 5v. Is this within an acceptable range or should I be checking the pinout on the back of the PCM as well. I'll also be flip floping the injectors and pulling the passide plugs to see if my lean condition follows to the driverside. I'll check the plugs to make sure they aren't fouled out.
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Old Jun 22, 2011 | 07:22 AM
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I had knock all over the place I could not track down before. I ended up pulling my knock sensor out of the block, cleaned it, put new sealant on the threads, torqued it to spec, and no more knock. Sounds like nothing I know but it worked.
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Old Jun 22, 2011 | 04:49 PM
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Anyone else?
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Old Jun 22, 2011 | 08:09 PM
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I had an intermittent knock sensor problem that we found on the dyno last year,ended up being a bad sensor,if you do replace yours only buy a delco part from the dealer,these things are very sensative.
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Old Jun 22, 2011 | 08:48 PM
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Does my circuit voltage sound ok at around 4.2v? Also, when did you see your knock appear? Mine seems to start after the car gets hotter around 180-190 deg.F.
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Old Jun 23, 2011 | 01:31 AM
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It will not start reading until the computer goes into closed loop, it would do it at any rpm intermittent, I was chasing a intermittent surge going down the track and my times kept fluctuating, put it on the dyno and found the problem,changed the sensor and problem fixed.
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Old Jun 28, 2011 | 08:10 PM
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Well, I think I have resolved my issue, and I'll findout for sure tomorrow when I can drive and log the car. I replaced my KS wiht a new AC Delco one and when taking the old one off I realized I really torqued the hell out of it installing it as I damn near needed a breaker bar to start unscrewing it and also I put a ton of thread sealer all over the threads. Two NONO's for a ks install. So this time left the thread sealer off and torqued to the proper 14lbs. Keeping my fingers crossed.

Also, bought a new multimeter and now I'm reading the proper 5v in the circuit so I know it's not that.
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Old Jun 29, 2011 | 07:09 AM
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Me win prize?
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Old Jun 29, 2011 | 07:48 AM
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Originally Posted by Mystery Bird
Me win prize?
Not 100% sure yet as I'll find out today when I can get her out and log it. However, as tight as that thing was on and all the thread sealant on there that has to be my issue. We'll see.
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