MS3 knock sensor wiring question.

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GeorgePatches
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MS3 knock sensor wiring question.

Post by GeorgePatches »

I'm setting up a 305 TBI with a MS3 and I'm planning to use ON/OFF knock control with a GM knock module as referenced in the instructions here.

http://www.msextra.com/doc/pdf/html/MS3 ... .4-39.html

I'm not understanding if I need to build a protective circuit as referenced on the next page?

http://www.msextra.com/doc/pdf/html/MS3 ... .4-40.html

Or if I need some other kind of protective circuit for use with the GM knock module or don't need a protective circuit at all?
KAT PWR
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Re: MS3 knock sensor wiring question.

Post by KAT PWR »

I haven't done an analog setup but, I would say after reading you need the protective circuit. internal mode is only if you get the knock and add-on board.
Matt Cramer
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Re: MS3 knock sensor wiring question.

Post by Matt Cramer »

With MS3X, you should be able to run the signal into a switched input on the MS3X and have it work fine.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
GeorgePatches
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Re: MS3 knock sensor wiring question.

Post by GeorgePatches »

I actually found the answer on the megamanual website for the MS2.

http://www.megamanual.com/ms2/knock.htm

The signal output is going to come in at 8-10 volts from the GM module, so I need to build that circuit with a zener diode to bring it into the 0-5 volt spec for JS4 or JS5.
prof315
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Re: MS3 knock sensor wiring question.

Post by prof315 »

GeorgePatches wrote:I actually found the answer on the megamanual website for the MS2.

http://www.megamanual.com/ms2/knock.htm

The signal output is going to come in at 8-10 volts from the GM module, so I need to build that circuit with a zener diode to bring it into the 0-5 volt spec for JS4 or JS5.

DO NOT USE THE MEGAMANUAL! It's obsolete and some of the info is actually wrong . Use the manuals linked at the top of the page.
Linfert Performance/321 Motorsports
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SCCA 2023 FP National Champion Tuner/electrical engineer
100s of MS systems built installed and tuned
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Matt Cramer
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Re: MS3 knock sensor wiring question.

Post by Matt Cramer »

The MS3X digital inputs already have the clamping circuit installed.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
GeorgePatches
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Re: MS3 knock sensor wiring question.

Post by GeorgePatches »

Matt Cramer wrote:The MS3X digital inputs already have the clamping circuit installed.
I have a MS3 Base though. Is there a CPU input other than JS4 and JS5 I can use to accomplish this without a protective circuit?
prof315 wrote:
GeorgePatches wrote:I actually found the answer on the megamanual website for the MS2.

http://www.megamanual.com/ms2/knock.htm

The signal output is going to come in at 8-10 volts from the GM module, so I need to build that circuit with a zener diode to bring it into the 0-5 volt spec for JS4 or JS5.

DO NOT USE THE MEGAMANUAL! It's obsolete and some of the info is actually wrong . Use the manuals linked at the top of the page.
Well the manual at the top of the page it's not clear if I need a protective circuit, nor does it give me any details on how to configure the MS3 with the GM knock module (going high versus going low). This at least clarifies what I had questions about.
prof315
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Re: MS3 knock sensor wiring question.

Post by prof315 »

The schematic on page 40 ( linked in your original post) is what you need. I 'm not sure what your confusion was.
Linfert Performance/321 Motorsports
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SCCA 2023 FP National Champion Tuner/electrical engineer
100s of MS systems built installed and tuned
Support the developers!
66FairlaneGTer
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Re: MS3 knock sensor wiring question.

Post by 66FairlaneGTer »

Did you ever complete wiring to your SPR3, and if so, did it work as you hoped it would?
1966 Ford Fairlane GTA, 428 EFI (Working on it); 1986 K5 Blazer, MS3 - 383 Stroker ...Jesus, Wife and Kids MUCH more important!
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