Odd problems with 2007 Sierra - knock at idle

[MonkeyGod]

So I am remotely helping a buddy out with getting his Sierra tuned up. Its a 6.0L with a TVS1900 and a medium cam. Cam specs: .597 / .578 220* / 230* 115* lobe.

It came with an out of the box magnuson tune. Some problems the truck had from the get go...tossing misfire codes, and torque converter lock up issues. I made some changes starting from the magnuson tune. Scaled the injectors, a few other things. Adjusted VE and MAF to get it in the ball park. The truck was misfiring so much that I desensitized the misfire tables (which I hate doing, this cam should not need it) but we needed to get it tuned and it wouldn't run very well in safe mode of course.

We got part throttle tuning down pretty good, and then started working on PE and PE entry points. The more and more he drove the truck, the more and more knock became an issue...even at idle. The magnuson tune has more timing than stock, so I reduced timing back to stock and disabled burst knock (quite common for roots blower setups) to see if that would help...hell I went with even less timing than stock.

Knock is getting worse. The mechanic who did the install tore into it again, double checked the cam and valvetrain and looked for intake leaks. Cam was never degreed with a wheel but is dot to dot. Mechanic says everything checks out.

I have never seen a vehicle knock at idle if the fueling and timing are even remotely close to where it should be. Mechanic swears its not mechanical, so I am hoping I missed something in the tune and could use some extra eyes.

I am posting the current tune and a recent log. I have advised the owner not to drive it until we can get it figured out. Thanks for looking.

[tom's2005gto]

Tried a few things tonight. Did the crrank relearn. Also wondering if maybe it's a bad tank of gas? So I added a bottle of 108 octane boost to the tank of the 24 (?) gallons of fuel that was already in there.

results = no knock at idle and only knock recorded was twice. First was during a test drive and made a 50mph short light run down the street with local traffic. Got to my turn around point and hung a u-turn around a sharp corner and while little or no throttle it record a 1 and a 4 = odd. Then on the way back to the house running 50mph and rolling up a hill it begin to bog down wanting to downshift but it didn't and I could tell it wanted / needed to so I put my foot in it just a bit more and we hit some 6's and an 8 and as soon as the tranny downshifted the knock was gone.

I think I am going to safely drive the truck as much as possible to burn off the rest of this tank of fuel and replenish asap.

anyone else have any thoughts or suggestions?

[Atomic]

Is the exhaust banging against the frame or something? Could be a vibration from somewhere else the computer thinks is knock but actually isnt...the tune should drive fine, but I would like to see the fueling a little closer, personally. What injectors are in there? The only data changed from a stock 5.3 is the flow rate table. If you are using different injectors you need the correct data.

[vette_c6]

try this file
post a Scan and lets me see

its not a tune

post scan

[tom's2005gto]

Is the exhaust banging against the frame or something? Could be a vibration from somewhere else the computer thinks is knock but actually isnt...the tune should drive fine, but I would like to see the fueling a little closer, personally. What injectors are in there? The only data changed from a stock 5.3 is the flow rate table. If you are using different injectors you need the correct data.

It does have aftermarket headers and catted y pipe and a magnaflow muffler welded in the stock pipe. We have put it in the air several times and rechecked everything. Haven't found or heard anything banging or clanking around. One thing does make some racket. The steering column knocks around, I had it checked when i bought the truck in December and was told that it's a common problem due to a joint that the grease leaks out of. I have deliberately driven over some very harsh roads and can feel the knocking in the steering wheel all while monitoring knock on hpt and it does not detect it.

Just thought I'd mention it.

[tom's2005gto]

try this file
post a Scan and lets me see

its not a tune

post scan

will do. thanks!

[MonkeyGod]

Either the CASE learn or the octane booster has made the low end knock go away. Hes going to flush out the gas and get some fresh gas and we will go from there.

[Gh0st]

case relearn makes sense

[IDRIVEAG8GT]

Scaled the injectors? What size are they? What process did you go through scaling the injectors?