hi, i have this issue since a month, when im datalogging the car and floor it in 3rd gear from 2000rpm as soon as it reaches 2800-3200 theres a weird powerloss, the car goes then slows down again and then goes again as this happens the cel on knock flashes like crazy, if i do the same thing from say 3000 rpm and floor it there is no knock...or if i floor it in second gear from 2000 it doesnt happen either, what is causing this...it only happens in 3rd gear from 2000 rpm...

here is my ignition map..

 

log it see what load your hitting its prob the -8 s/-6 s etc in the timing map

 

I have the same exact problem at 2800-3000rpm,the power loss im guessing is from the knock pulling timing.I have a built 2.0 no balance shafts and on S.D. I cant figure out what it can be.Messed with the timing and fuel maps and still have this problem.Like the O.P. said i can step on it after 3k and no knock.

 

You guys may need to adjust your knock sensitivity. I had a similar issue that turned out to be phantom knock from my downpipe hitting a tie bar. I adjusted the tie bar and adjust the sensitivity a little in the low load rpm range and now its great.

 

In your logs you can capture knock voltage versus the knock_adc ( i think that is the field name) and see if you are getting big spikes from knock or there is some noise that is right at the knock sensitivity curve. If it is noise you can adjust the map to be less sensitive in that area, essentially you are moving the knock sensitivty curve up. But do not adjust too high as it will need to capture any true knock spikes you may be experiencing. Good luck.

 

You need to post some logs with load, RPM, AFR and knock captured

 

hey sorry guys for not updating the knock has gone away...apparently i was very low on timing in that range i upped the timing from 70-100 load and 2500-3500 rpm and it went away all is good..thanks for your time and help! cheers!