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2007 Yukon Xl
6.2l with Truck Norris Cam and Long Tube Headers.
I am new to tuning. I would like other opinions as I am learning as I go. I am currently working on Speed Density Tuning and I am getting KR. I have raised my knock sensors 25% and it is still showing up. I have attached a Log and tune. Can someone check it out and let me know if you think it is false knock or if something is wrong? Also any Ideas as to why the engine damn near stalls when I put it into gear would be a help.
Add Burst Knock to your logs and I bet you will find out why. Next return your knock sensor levels back down to normal. This will help you: https://youtu.be/c7rzX6DZPqY?si=8DuoMQ_wnfL_CPI4Quote:
Originally Posted by Maverick70080
I'm sure the experts will come by soon and give you the more, better answers, but from what I can tell based on my experience with a very similar cam and O/R exhaust; I had to do to the following.
Put your knock sensors back to stock, you're not anywhere near a place where you want to mess with them yet. You still have burst knock and piston slap active, you should probably shut those out at least while you're tuning. In IAT Spark Advance Correction, you're asking for it to start pulling timing at very low IAT's and your ECT Spark Advance is pulling timing at operating temps.
You're only commanding 20* of timing in your High / Low Octane and Base Idle tables, at Idle range; you probably want to crank that up 5 or even 7* to start out with that cam. In your "IN Gear and P/N" spark adders, you probably also want to add 2 or 3* to the colder temps and ramp it down to zero at operating temp. I don't know what else you changed in terms of idle airflow and timing, but you should definitely make sure all of your idle RPM settings align. One of your start up idle RPM settings was different than the rest, I think it was "In Gear" but I don't have that setting in my ECU so I'm not familiar with what it does because start up in gear shouldn't even be a thing.
I would disable the virtual flex fuel. Next thing, I would turn on STFT's and leave LTFT's off. Tune the low rpm stuff with the narrowbands. You have plenty of base running airflow, so that shouldn't be the stalling problem. Your Hi RPM spark table has timing locked at 20 degrees like your idle table. Put the HI RPM area where you have 20 degrees in the block, back to stock ( I did the same thing). Get your VE table smoothed out---it will be more accurate with narrowbands. When you get your spark and fuel smoothed out, the little retard blips may go away.
You should verify if it is burst knock or real knock. There is a burst knock pid.
I very very rarely touch the knock sensors sensitivity on these. I would put that back.
You've tried premium fuel right? As knock sensors age they either get quiet or pick up all sorts of false knock.. New knock sensors torqued properly might be a good idea.
That was a very informative video. Thank you for sharing.