I'm worried about misfires. Log inside.

[AndyTA]

Hello Everyone,

I'm willing to provide whatever the board needs to help me.

New to tuning, but have been doing lots of reading. I'll get right to the point: (Gen 4 engine with Gen 3 PCM, 1999 LS1 originally)

I'm really concerned/worried about my o2 readings. The logfile attached is me getting close to finalizing the VE table (MAF Disabled of course). During Idle, one of my o2's will go full lean, the other full rich. Also, you'll see sometimes during acceleration or cruising at a higher rpm like 3,000ish, the same issue exists.

What else is wrong electronically, based upon the log? Aside from a few lean areas I need to fix in my STFT table.


I did lots of reading, and that's what has made me worried. This is a new swap:

New plugs
New wires
Used Truck coils
LS 427 Gen 4
Baby cam @ 235/244 .629/.615

Any direction or troubleshooting tips would be greatly appreciated. I'm kind of at a loss. The misfire code throws itself right away the moment I enable MAF. However based upon NB02's, the misfires truly exist?

Can any of it be attributed to an incorrect fueling table, or, am I looking at deeper mechanical issues or simpler ignition related issue?

Thanks everyone,
Andy


This is my first post ever on HPTuner Forums. I apologize for any wrong-doing in any fashion here.

[5FDP]

Why not log the misfire with the scanner to see what it shows you?

I'd also be using a wideband and no o2 sensor control to really dial in the fueling in open loop first, then go back to closed loop with fuel trims to see what it's like. A wideband is a must anyway, they do not work under full throttle/power enrichment.

[AndyTA]

Why not log the misfire with the scanner to see what it shows you?

I'd also be using a wideband and no o2 sensor control to really dial in the fueling in open loop first, then go back to closed loop with fuel trims to see what it's like. A wideband is a must anyway, they do not work under full throttle/power enrichment.

Thanks for your response!

1) I didn't think about that. I'll see if I can figure out how to do it first, before I ask.


So this might be a really stupid question with a super obvious answer, but:

Is it possible for misfires to be caused by a non-calibrated MAF? (I am wrapping up VE, and will move to MAF tuning next. But I was concerned about the misfires and wanted to address that first if it wasn't caused by the MAF itself anyway).

Thanks again,
Andy

[AndyTA]

Hello,

I cannot get my "Misfire History Cylinder" channel to work. They always read "0" even though my "Current" is having misfires counting.

Do I need to have the "total misfire" channel as well?

Thanks,
Andy