My car is getting all kinds of false knock 9 degrees on start up and idle. I want to figure out a way to find the cause and fix it. The car used to never show knock retard unless I was whipping on it on my old setup(7 psi P1sc, boltons and stock motor).

 

I'm guessing you already have the lt4 KM. Do you just get it at idle or all the time? I used to get 7-9 degrees at idle and 2-4 when cruising and 5-8 when at WOT. I ran some 104 octane in it and it still did it which leads me to believe its not real knock. I'm heads/cam on stock bottem end so my motor should be fine on pump gas. Mine was picking up false knock from somewhere and we never did figure it out, I even changed out the knock sensor. Finally I just programmed it out at wot. I also had a friend with a 94 z28 with an ati procharger on it and he had the same problem back when he had the car.

 

I get it all time the, even when it was full of 110 octane i was still seeing between 5 and 9.

 

A bad knock sensor, if the wire is bad or the knock module itself is bad you could see what you're describing.

I supposed you'd also get it if the knock sensor isn't torqued properly.

 

I tried different knock modules also, and torqued the sensor to different specs and still got the knock reading.