I was doing some datalogging yesterday, using Datamaster. During playback I like to check and see where the knock counts are, spark retard, map and rpm. This tells me if I need to learn how to drive, or if I need to pull spark or add fuel. I noticed that I gained two knock counts, with no spark retard. Now I've seen spark retard of like .1 or .3 with no knock count, but not the other way around.

Any ideas or should I just shut my mouth and go home?

 

if theres not enough instance of knock iun a certian time frame there will be no retard but the knock sensor it self being active will show up on a scan. also the knock retard could have been so short and minimal that it wasnt in the data stream.

 

What you are seeing is the ECM doing its knock sensor test. It will test for knock without activating the knock retard routine just to make sure the knock sensor is working.

 

interesting thought about the ecm performing a test on the sensor itself, as I had already accumulated 5 knock counts, with spark retard within the 15 mins or so of data I had collected.

Guess I'll just ignore it and continue to play with it

thanks