The setup:
'92 Vx Chassis
D16Y8 block/head
eagle rods
srp pistons
supertech valvesprings/retainers
crower 2 n/a cam
hx35
Walbro 255 Inline
DSM 450's
Engine ran perfectly until i decided to track the car at Thunderhill. Overheated, blew a HG, cracked a piston skirt.
Tore apart the engine and rebuilt it, now i'm plagued with a misfire. At high rpm (6,500-7,000) it takes a little over atmospheric pressure to cause misfire. At low rpm (4,000) it will misfire around 3-4psi. In vacuum car drives perfectly.
O2 sensor reads 21 afr during misfire. I have also attached a video of the misfire while standing still.
Things I've tried:
Replaced Dizzy
Plug wires
new plugs, even tried gapping down to 0.020"
quadruple checked mechanical and ignition timing
adjusted valve lash
threw in the stock cam for shits and giggles
Hot wired the blk/yel wire on the dizzy in case it wasn't getting enough juice
I'm almost ready to put a 12Ga slug through the block.
Engine misfire