RSMike

iTrader: (1)

notice the removal of black coating around the bore on the headgasket.
This is common on SR20's with the cylinder liners moving.
It seems you are have either bore movement or head movement.

What headstuds and torque settings are you using?

240Z TwinTurbo

iTrader: (25)

I run the MAP Ultimate Duty H11's torqued to 95-100 ft/lbs. I am suspect of my torque wrench so I will borrow one that is known to be good. I will run the car through a few heat cycles and let sit overnight. I can then back each bolt off approximately an eighth to a quarter turn, then re-torque to spec one at a time and in sequence. I pushed it too much before I decided to pull out the laptop and actually log wideband AFR's, which were lean.

03whitegsr

iTrader: (8)

I've seen guys induce problems by backing off head bolt torque to retorque instead of just going back over and checking them.

Or leave them 10 ft-lbs low to start with them bump them up that 10 ft-lbs after a heat cycle or two.

With the H11s, even at 85 ft-lbs, you are still above factory torque level.

240Z TwinTurbo

iTrader: (25)

Unfortunately, you have to back off the bolt so the static friction is lower than the targeted dynamic friction allowing you to reach the desired torque spec. I guess I could leave the initial torque setting somewhere below 95ft-lbs, but I never had issue on my 240Z(inline 6) backing off then doing a re-torque one at a time in sequence.

caged

Get an old plug and open up the gap and then it should show up on the timing light, iv been down this path before.

I Am actually having similar ignition misfires myself, im running a Vipec. I might start looking at the exhaust cam sensor as what JohnBradley said was interesting.

RSMike

iTrader: (1)

Check your "trigger errors" in "Runtime Values", that will show you if you are having triggering problems.