Hello, all

I am trying to stop a high rpm knock that i have been chasing for some time now, it is a 730 ecm. Here is my question tho, I had lowered the Knock Retard amount that is allowed down from the stock values all the way down to 4*. Now when i put my scanner on it the highest KR that it see's at WOT is 3.5*.
My question is "if" the value is lowered down to this point will the KS still show the actual Knock counts the engine is experiencing? or will it show only the 4* that i allowed it?
I am having a time getting it to stop , i really wanted to "hear" it or see some sign on the plugs. Neither is showing anything out of the ordinary at all. BTW i do have a short scan that if any one is interested in seeing i can sent it to them thanks.

 

With spark knock, counts and retard are two different things. Usually counts are accumulative and then roll over. If knock counts arrive, they are noted, but not always acted upon.

Spark retard on the other hand, can be disabled. There is usually a lower temperature, MPH, and/or RPM threshold before the ECM will retard the timing. So there can be knock counts but no spark retard.

I have always gone by the plugs as to whether knock is truely present. To me, if they don't show knock, then the knock detection system is picking up false knock.

RBob.

 

Thanks rbob,

I too think that it is false KR, tho i do have a fairly noisy ValveTrain, RR etc
I just pulled the plugs today and i see no visible signs of deto, I am only getting the KR at WOT and only when the ecm is in PE. The entire time the car is driven normally there is Never a KR shown on the scanner even when under hard accell. ( not WOT ) Maybe i will return the KS to the stock setting just to be safe and just reduce the PE spark adder and see what happens.