help with 2jzgte hiccup at wot stop boosting and goes to boost and hiccup again

[Hpaddict]

hi all, i really need some advice where to look and im running out of idea of finding the source of the problem..
my car is a nissan cefiro a31 with 2jzgte swap 5speed

here is the problem:
i can boost normal up to 17 psi on 1st and 2nd gear nicely BUT on 3rd,4th and 5th gear the boost is going up and down, so its like WOT(15psi) and cut then boost dropped and raise back to 16 then cut again and go up to 17psi, and kept on going like that.until stock redline..and im sure its not a fuel cut, its like a hiccup when the cut happen and less than a quarter of a sec(more like a flick)..any idea what is going on? or where to look?


here is my mod:
-JDM 2jzgte+OEM Aristo JDM ECU
-twin oem jdm turbo
-3inch custom pipping
-FMI
- Gizmo Boost controller (include BCC)
-3inch exhaust straight pipe
-044bosch fuel pump
-malpassi fuel pressure regulator
-Apexi AFC
- fuel surge tank.
-ngk iridium spark plug.

thank you

[Daddio]

Sounds like fuel cut or possibly a knock sense? Fuel cut (boost cut) will occur at 15.5-15.8psi after 1 second of boost over 15.5-15.8psi as read by the MAP sensor...in first & second you might be over 15.5psi too briefly for fuel cut to kick in, however in third and higher the build of boost pressure is more gradual, resulting in fuel cut. As rpm's increase, boost builds faster, hence why you can get 'spikes' past fuel cut rpm which get bigger as rpm increase. Knock sense will usually drop to limp mode, but can just pull a bit of timing (and slow down boost generation) for minor occurrences...
You dont mention if the engine is throwing any codes? Suggest you run diagnostics and pull codes and see if anything is being stored.(I am assuming non-vvti 2JZGTE?)

[Hpaddict]

Sorry forgot to mention, no i didnt get any codes, yes its a non vvti 2jzgte..this is the thing that confusing me, it does sound like fuel cut, but im sure 100% its not fuel cut, when you hit fuel cut you cant go pass the fuelcut point, and it feel like you hitting a brick wall when it happen..but this is not...even there is a hiccup my rpm keep going up and so is the boost,..but when the hiccup came my boost is dropped but i can get a 17psi boost..funny thing is this also happen when the swap is still fresh, and without fixing anything its gone...and now its back again after couple of month..i also checked if there is any vaccum and boost leak but i couldnt see one...

[dnegative]

I have a 1JZ that does something similar once a blue moon, you will be motoring along @20psi and it will drop back to 17psi and then cycle back and forth. Still runs pretty rich and the spark-plugs are still intact with no aluminum on them so I haven't given much of a fuck.

Runs a Gizzmo FCD