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

any ideas, guys? someone's certainly had a similar problem......