Diablosport Forums

I updated to the v 8r10 a few weeks ago in my 2007 Tahoe. It now knocks and pings pretty bad with the 87 performance tune. It did not do this with the previous version that was in the tool when I purchased it. I have since removed the tune as I was concerned. Any ideas?

Thanks

You really should not have heard any knock, as the knock sensors will generally pull timing before there is sufficient knock to be heard.
Hook u p the Predator and monitor KR under the live data menu, and see if it goes over '0' at any time during WOT.
Then install the tune and repeat this procedure.

If there is KR, you may just have some really bad gas in there.

Thanks

i was gonna say shit gas also.














shit gas.

I still get the knocking @ WOT, running the 93 tune on my '08 denali... I've got my own thread running on this issue. Lew has helped me get my LTFT's in line, but I need to get the knocking issue fixed. I run Exxon 93 and Amoco 93...have been running them since I got the truck ~5000 miles ago.
Mike, do you have some suggestions?

Try logging the stock tune to see if it has KR....that will point to crap gas.

Thanks

I tried that before. I didn't have any KR when running stock tune.

Actually that was the first thing I did, after receiving my tuner and installing the performance tune. I noticed the pinging immediately upon WOT. Not wanting to cause any engine damage, I restored the OEM tune...and drove it that way, until I had some time to investigate and work with it. So, I have some time to work with it, I started the other forum string about knocking...and Lew helped me get my LTFT's dialed in... with great success, but I still cannot jump on it, or I get considerable audible knocking.

Thanks for the quick response. So where to from here? I've had 4 other Diablo tuners for various vehicles...and never adjusted anything with them... I installed the performance tune and drove them without problems...until this one.

here is what I would do.... install the 87 tune with 93 gas in the tank. monitor for KR at WOT for a few runs.... if you dont get any KR, go into "modify tune" and then "modify parameters"...you will see PE spark. adjust your tables starting at about +4%....install "modified tune"...then check for KR at WOT again... just keep advancing timing in this manner until you get KR with your tuner, then go back in and back it off a few %.... keep in mind, you should be around ~20* of timing at WOT, so adjusting 4-5% of that amount isnt very much.

then, monitor your fuel at WOT, via your AFR readout if you have it, or your 02 mv's if your tuner shows that... you want around 12.6-12.8 AFR at WOT, or .880-.890 mv at WOT on the o2 sensors. only monitor bank1 sensor1, and bank2 sensor1.

let us know what you get after all that tuning.
good luck man.

If I flash to the 87 tune, should I modify it to reflect my slope injector setting of -10? Lew showed me how to get his adjustment... I want to keep the response. Assuming I install the 87 tune with the -10 inj slope... do I have to drive it to let it set in, or are the parameters adjustable immediately?

Thanks for the quick response. I'm still learning how this works.

no.

set it to the preprogrammed 87 tune, and tune your LTFT just like you did with the 93 tune..... or you could just retard timing like i stated above in the 93 tune, since your LTFT's are already dialed in. just back it off until the KR disappears, and go from there.

either will work, which ever is better for you and less frustrating.

Thanks!

NO PROBLEM MAN. IF YOU NEED TO , PRINT ALL THIS OUT AND USE IT, AND PRINT LEW'S STICKY OUT. THATS WHAT GOT ME INTO LEARNING MODE ON THIS TUNER, AND LOTS OF READING. LEW KNOWS HIS SHIT!

I guess it is bad gas in the Dallas area. Running the stock tune I get a KR of up to 5 at very low load, and 2-3 under heavy load. I was empty and purchased fuel from a different supplier (QT 87) and still have KR. I guess I will stay with the stock tune, 87 octane was $3.05 here today.

wow! 87 is $3.19 here.... but i HAVE to run 93, which is $3.42

damn, wish it was that cheap here...

I run 93 in the Monte, and it's $3.69 here...

the occasional 100 octane I put in (CAM2 / Sunoco GT 100) is about $7.89...

good lord. just think if you had a fast car...you would really need that high octane!