lt4 with a 2650 tune

So we're tossing a Kong ported Edelbrock 2650 on a cammed LT4 Z06. The car was tuned by someone else originally and we figured we would start by just updating what we needed. Dialed it in on the street without any real issues. Car seems to drive fine and idle ok but as soon as we floor it on the dyno it just sputters and makes not power. The bank one o2 sensor kind of goes crazy while it sputters and then drops very low. Any ideas what would cause this? We smoke tested the car and it doesn't seem to have a vacuum leak or anything. Attachment 103255Attachment 103256Attachment 103255Attachment 103256

Bank 1 is going low as you indicate. There's certainly a problem on that side. I would start by looking at the plugs and wires. Make sure that none of the plugs are cracked. Look at the gaps on them and ensure that they aren't closed up.

Went through them already and they look fine and I had no misfires on the scanner......Looking at the tune though the previous tuner turned off all the misfire charts. I'll toss them back on and see if I can find anything.

Do you think a misfire would cause that bank to fluctuate like that? I always just log for misfires and never really looked at what they make the o2 sensor do.

If the previous tuner turned off all the misfire charts, i'd start from scratch.

I turned the misfires back on and they still don't read in the scanner. Air fuel is spot on but the car just chugs. Is there another way to turn misfires off other then the engine diag misfire page?

heavychevy I might just start from a new file if I can't log these misfires.

Does anyone have a stock 2016 z06 a8 tune?

Your MAF diagnostics are all disabled. Misfire detection will not run unless the MAF checks out.

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Originally Posted by JASON11WS6

Any ideas what would cause this? Attachment 103255Attachment 103256Attachment 103255Attachment 103256

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If the engine coolant temperature is below 73 degrees, my Z06 switches off the power at 4,000 rpm.

I uploaded a stock one in repository a good while back.

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Originally Posted by smokeshow

Your MAF diagnostics are all disabled. Misfire detection will not run unless the MAF checks out.

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I caught that and updated those fields but the issue remained. No, misfires. I would just replace all the wires but they have a coil relocation kit and the wires aren't standard LS wires.

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Originally Posted by orrwhat

I uploaded a stock one in repository a good while back.

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Thanks, I'm going to give this a try with the new maf curve

I had an issue just like this about a month ago. All spark plugs looked great, no crack or fouling. I had exhausted all possible issues. Went back and installed all new spark plugs, and it fixed the issue.

You might want to swap spark plugs from bank to bank to see if the issue follows. this will tell you if you have a bad plug somewhere.

Yeah it was the wires. The plugs were already new. Finally make a clean pull with no misfires and we get knock of coarse so the battle continues.