Just wanted to share this wiring diagram for anyone interested in adding a knock sensor to an engine that didn't come with one. Obviously would be beneficial for any engine that may be prone to detonation, especially for boosted applications (turbo, supercharged, nitrous, etc.)

 

Find an ESC controller and a knock sensor from a 1983 to 1986 GMC or C10 pickup or van (also Jimmy and Blazer) with 305 engine

 

This can be used on any engine, doesn't have to be a 305 or a V8..... it can be used on ANY engine that has a distributor and a magnetic pick up coil. The module doesn't have to necessarily be inside the distributor... it can be externally located. Same goes for the coil, it can be externally located if not using an HEI distributor. Just run 12 volts to power the module, coil, and ESC controller. The wiring diagram shows how this system was originally wired in the HEI distributor. This ESC controller does not control ignition timing... the mechanical and vacuum advance mechanisms inside of the distributor does this... this ESC controller only changes timing (retard) if knock, ping and detonation is detected. Slightly retarding timing if light knocking is detected... more retard if heavy knocking and detonation is detected and leaves timing completely alone if no knock.

 

Make sure you have good motor mounts to prevent false knock. Make sure your engine doesn't have carbon buildup in the combustion chambers, especially if it is high mileage. Run a good fuel system cleaner. Make sure your engine doesn't run hot. 180 degree thermostat is preferred... or lower if racing. Use high octane for high compression or boosted engines. Make sure your engine is timed correctly... an over advanced distributor will cause the ESC module to constantly retard timing.

 

You would probably want to get at least the connector pigtail to the ESC controller, as it isn't easy to connect wires to that box without one. Obviously getting harder to find 80's vehicles in a junkyard these days. I found mine on ebay with harness. Easiest way to find these ESC controllers is to search by GM part number 16029011 and/or 16042121

 

You don't necessarily have to connect the tip in vacuum switch (yellow wire). It's purpose is to retard timing for maybe a split second when you step on the throttle (when vacuum suddenly drops)... this vacuum switch is connected via a vacuum hose to the intake manifold. Regardless, this vacuum switch can be hard to find in good condition. There are a few different knock sensors you can use (depending on what engine you use)... make sure the knock sensor is between 90 to 110k ohms resistance.

 

😉