Stock 2jz twin turbo - breaking down at full throttle or under boost.

[wrench]

Sorted out the over fuel at idle problem, turns out the factory fuel pressure regulator was jammed shut... add it to the list of things that have been wrong with half cut so far. Thats all sorted, using malpassi atm just so i can drive it, standard SARD unit is on the way.
Anywho, went for a burl... have read things about how the ecu needs to re-learn after being disconnected from 12v for a while. Half throttle is ok, full throttle it crackles and farts and carries on, or as soon as you go onto boost. AIR/FUEL gauge looks fine, temp is good. I pulled up, jamed it in neutral and it free rev... a little hesitant though, but got it to limiter.
I have put new spark plugs in it a couple of days ago. Could it be a coil???
The old spark plugs had rust around the base of them, i think my half cut must of spent a bit of time out in the weather before i bought it. It has been under cover with a bonnet on it ever since i owned it.
I have also read about " artificial limiters " on the aristo JZS147, something else to consider?

[Duk]

It's a common problem for RB20/25/26 to suffer from dud coils, typically cracked insulators.
Whip them out and look for any signs of straying spark energy (burnt insulation). If you find any, try adding some tape around the outside of the insulator. It is/was a band aid for the Nissan crowd.
After that, get your hands on a known good set to eliminate possibilities.

[wrench]

Is there any other way to test coils except for pull them out and try another one?

[Donmik]

I second Duk's theroy...

My mate has a GTR and had exactly what you just explained, he spent so much time playing with all these little odds and ends but there was no improvement...
So he finally bit the bullet and ordered new coils packs!!! Instant fix!!!!

[wrench]

Coils no.3 and no.4 were testing a little high, book says resistance should be between 0.5 and 0.85 ohm , mine were reading 0.9. I have a very accurate Hioki multimeter too.
I tried taping them up, didn't make a difference.
Now it wont free rev past 4000rpm either. So the coils are shot?
Also another idea... it wouldn't be a boost cut or something silly like that fucking it around?
The only other thing i could think of was that i have disconnected the ISCV on the intake, both at the plug and blocked off the vacuum line that returns to the turbo manifold. I actually am using the old ISCV hose for my brake booster now.
I just blocked it off on the turbo side.
Could this be upsetting anything?
( the ISCV was jammed open, thats why i have disconnected it all ).