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I'm interested in installing a knock sensor on my big block. I have the sensor installed in the block, and the control module, but need to know how to hook it all up. I'm running a Holley MPI Projection multiport fuel injection system, so I have a computer controlled HEI distributer. I assumed you could hook up to the computer, but Holley tech support said that can't be done with the system I have, but would work with the newer 950 MPI system. They suggested I buy a Chevy knock sensor harness, but when I went to Chevy, the blank stares were followed by a half hour of searching thru their books with no luck. Does anyone have a schematic of how they are connected, or any experence with knock sensors and Projections systems (I know that is a stretch, but I had to ask). Thanks to all.
Wilbur
 

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Knock sensor harness?? No such animal It's part of the engine harness.
Knock sensor works by using a piezio crystal as knock is detected a vibration causes excitation inducing votage this is picked up in ecm software and used to generate a retard signal to the dist.

Highly oversimplified but thats what happens
 

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Is this a GM sensor? What module? The one from the older efi systems?

Go to www.diy-efi.org and get the schematics for one of the older computer systems from the GM ECM part of the site. It will show how the sensor and module wire up. Basically, it's power, ground, output, and sensor to the module. I believe the output of the module pulls low when knock is detected. I know you can hook it right to a light so the light flashes and comes on when it's knocking.

Peter
 
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