I turned off my knock sensors at 3K RPM but there's still knock!

[88LS7MonteSS]

I went into the PCM and on the "knock retard attack" tab under spark and set the RPM disable at 3K RPM...this shutoff knock retard for tuning (I have been running richer than 13:1 so I wasn't too worried about being lean!) and I never saw any knock...it was great! I went back on the dyno today and noticed that I have as much as 6 degrees of KR now....is there something else that I need to turn off now?

[SultanHassanMasTuning]

load on the dyno?

[88LS7MonteSS]

load on the dyno?

I had some knock last time on the dyno and the car was running N/A with A/F in the 12:4 to 12:7 range without a boatload of timing so I figured that it was false knock and just shut the sensors off above 3000 RPM. This made tuning much easier. I used that same tune on the dyno again yesterday and now I have knock above 3000 RPM and want to know what else should be turned off to eliminate this for WOT tuning.

[VodeAn]

Sometimes it can be difficult for me to tell the difference between false knock and actual knock even on the street. Vehicles with worn motor mounts seem to be more trouble than vehicles with solids. I could only imagine how frustrating it could be if a dyno was providing it's own feedback into the system. Do some dyno's do better or worse when it comes to triggering false knock by introducing a vibration through load? If I make an investment in one it would be nice to know which one's are prone to triggering false KR.

[SultanHassanMasTuning]

did you make a run on the street and see if it knocks?

[88LS7MonteSS]

Strange...... made more runs on the dyno this weekend and no knock! It left just as strangely as it appeared!!!

[SultanHassanMasTuning]

^bad gas?

[MikeOD]

Strange...... made more runs on the dyno this weekend and no knock! It left just as strangely as it appeared!!!

^bad gas?

Yeah...makes me think you don't have false knock...I think you have real knock, maybe from bad fuel.

[88LS7MonteSS]

Gas was fine.....like I said, it just went away as mysteriously as it appeared!

[mineralareatuning]

Whats the plugs look like?

[88LS7MonteSS]

Whats the plugs look like?

The issue is gone and plugs are fine

[ayousef]

do you have burst knock disabled?

[88LS7MonteSS]

do you have burst knock disabled?

Great question! Which tab would be tweaked?