This would drive most people crazy, but I am a calm one.

I keep getting spark retard, mostly from .1-.6 but sometimes even up to 4.1, with no increase in the knock count.

After doing a search in this forum, the only thing listed that seemed to be a possible culprit was "burst knock retard." I still don't know what it is... I'm guessing it has something to do with getting knock do to running lean? Anyway, I effectively disabled it by making the enable temp higher than I run (90*C), and I am still getting the same symptoms.

So, my questions:

1) What can cause spark timing retard with no increase in knock count?

2) What is burst knock retard?

Thanks, guys.

 

Does the lack of a reply mean that no one has figured this out yet? I would disable the knock retard altogether, but I know I do occasionally get real knock, and the count goes up, so I don't want to grenade my motor for making it run better sometimes.

Anyone? Please?

 

My understanding is that burst knock is not measured knock, but rather the pcm trying to anticipate knock and pulling timing to prevent it. It is activated by large changes in airflow at the maf sensor.

If you don't have nitrous or blower I don't think you really need to worry about grenading your motor. Since my car has had false knock issues I have removed all knock retard from the pcm.

 

OK, your description of burst knock retard is pretty much how I understood it.

The question is, if I've effectively disabled it by making it's enable temp higher than my car runs, why am I still getting retard with no knock count increase? Can something else cause it?

I do run nitrous, which is why I don't want to disable retard altogether.

Thanks again and I look for more of your insight!

Solomon

 

I disabled mine by setting all the entries of the table burst knock vs coolant temp to 0 degrees. I haven't seen any knock since. I don't know of any other causes of knock.

Joe

 

Are you guys using TunerCat or LT1edit?

Tuner Cat has a "Burst Knock Retard vs. Coolant Temp."
Maybe you could try zeroing that out.

I'm not a big fan of disabling knock retard....just in case.

I have the same problem as you have mentioned but I have been trying to determine what variables are causing the problem. So far it doesn't seem to happen at any kind of interval or temp.
I want to give that a try but its almost time to put her away for the winter.

 

I zeroed the table out for burst knock retard as two mentioned on here, and... WOW! I cannot believe the difference, the car feels so much snappier now!

Gone is the slight "lag" when you punch the throttle. Now it just GOES! I haven't gotten to scan it since to see if I'm getting any knock but it doesn't feel like it. I'll let you know once I find out.

Thanks for the help, guys!