I'm really stuck with this! I'm running out of idea's to try so ANY help would be REALLY appreciated!

Full engine spec:

Scat 383 Bottom End / AFR 195 Heads / Felpro 1010 Head Gaskets / 9.5:1 Compression / LT1 Intake & Fuel Rails / 30lb Injectors / Stock TB / Comp Cams 306 / 74deg Overlap / 230/244@.050 / ZF-6 Manual / Singlemass Flywheel / Hedman Headers / LT1 Exhaust / Small Distributor & External Coil

Now I've had a pretty major time trying to DIY tune this on a daily driver basis - WOT it pulls like a train and always has.

As the tune is getting closer I'm realising that I've actally got a misfire at light throttle/cruise. Its most noticeable as I get above 2000 rpm. It sounds like its just a single cylinder and its rather random, almost like morse code. Its not enough to cause the engine to stumble, but I can hear it and it just kinda "tugs" like lope.

I have just pulled the plugs (well 7 as the last is a PITA) and they are all so mixed!

Driver Bank: Porcelain / Strap
Plug 1: Light Tan / Tan
Plug 3: Brilliant Clean White / Tan
Plug 5: Tan / Tan
Plug 7: Black / Black

Passenger Bank: Porcelain / Strap
Plug 2: Dark Tan / Tan
Plug 4: NA / NA
Plug 6: Light Tan / Tan
Plug 8: Black / Black

I know that plug reading is more involved than this but I was rather shocked to see such varrying results - especially plug 3 in which the pircelain looked brand new, not a singe mark on it.

I will try some new leads, the Cap and Rotor are new. Its had a fresh set of plugs now. The only other thing I can think of is the injectors are not flowing equally? How can I test this? Any other ideas???

PLEASE HELP BEFORE I GO MAD!!!

 

Bring your plugs to NAPA and have the injectors cleaned and flow tested. They do this for a small charge (not sure how much). Better than replacing them all if they are good to begin with and just need cleaning. What is going on with plug #4? Black plugs are not good either.