misfire with no codes, need help please!

[mrialsm4]

ok guys, like the title says, I have a random misfire seemingly all in the 10"hg to about 5psi range.

it happens at very low load, but the misfire is sparse. at about 50% throttle it misfires pretty good, and at WOT it's hard to tell if there is any misfire at all. The misfire was non existent when I first took the car off out of the shop last week and it has progressively gotten worse over the course of a full tank of gas.

so far I've done the following;
changed plugs, plug wires, front O2's, and got some ohmic readings on my coilpacks and they were all consistent. I've checked the valve springs and rockers, and ran a compression check on the motor, all cylinders were spot on.

A month ago the car was running pretty good, with the exception of needing some idle tuning and a good autoVE. at this time I finally burned up my 3rd built 4l65, and figured it was time for a change for the better. I installed a TH400 with the supporting mods to support around 1000RWHP (RMVB, T-brake, 3800 stall). I also changed out all of my piping from my procharger to the FMIC to my throttle body.

the mods to the car are as follows-
lq9- 403ci 9.3:1
Ported fast 92 with stock DBW TB
95lb injectors @ 45PSI with versafueler driver box
Mast fuel rails with magnafuel pump and boost referenced regulator (not connected)
EPP FMIC
F1A procharger @ 16psi
Trickflow 225 heads
Kooks 1 7/8" headers/ no X pipe with 3" borla race mufflers (way too loud)
Harland sharp rockers
cam is- 224 int./230 exh., 0.581 int./0.588 exh.
TH400 with RMVB, T-brake, 3800 stall


What do you guys think that the next best course of action to take would be? I'm pretty much stumped since I'm not seeing any codes thrown, very strange......

Thanks for the help in advance, guys.

[mrialsm4]

Log_0054.efi

Here is a current log. It's short, but the miss is there during the cruising.
it was also my first AutoVE attempt after the new setup was completed.

[mrialsm4]

any ideas guys?

[joecar]

Your HO2Sx1 voltages show you are excessively rich at cruise...

(AFR_B shows 14.7 being commanded, but the HO2Sx1 voltages look like they would at WOT with an AFR richer than 12.8)

this might be the reason for your misfire;

also your MAP looks wrong (excessively low), which will cause the cylinder airmass to be mis-calculated;

it also looks to me like your injector tables don't match your injectors

(at part throttle cruise just past the middle of your log, the INJDC almost max's out... [with those huge injectors])

how much HP/TQ are you supposed to be making...?

[joecar]

Do you have a wideband...?

[mrialsm4]

No, they are not scaled properly. They are 2.5 times less than the 95lb rating, i had to a lot of doctoring to get it to even run. I have all of the airflow tables divided by 2.5, and am running a 2.5 bar map. In the log, the car is running olsd. It was my first autove with the new setup. I did put it back into cl fueling with trims and all enabled, and did achieve a lean cruise (14.7). The miss never goes away. Wideband is there. I logged it in the file. It's a plx.

[mrialsm4]

for some reason, no matter the AFR, I still get the miss. any ideas on what I should be logging to find the culprit? Let me know, and i'll post the log.
By the way, the reason I have everything scaled back is so that the large injectors will work properly with the "limited" parameters in the E40 ECM.
another funny thing is, when I was running a pretty much stock setup with SVO 42's the injector duty cycle was hitting outrageous numbers as well. my AFR was always pretty much inline with what was commanded after the initial AutoVE tune I did. I know that the 42's were enough for that setup, and I know that the 95's are enough for this.
as for horsepower, your guess is as good as mine. I modeled my engine build after this car-
http://www.exoticperformanceplus.com...Car.php?car=29
http://www.gmhightechperformance.com...tsv/index.html

[joecar]

Did you scale the MAP correctly...?

[joecar]

How severe/noticeable is the misfire (I'm try to get an idea of its magnitude)...?

Is it using up any coolant...?

[joecar]

You checked valve springs and rockers; what lifters, pushrods, rockers, springs are you using...?

You changed ignition components; did you visually check for spark using a spark tester like KD2756 (observe spark while snapping throttle)...?

You did compression test and all cylinders were sufficient and close.

I missed wideband AFR in your log, I'll look at it later tonite.