FC3S JDM S5 TII
Mods > Mushroom filter, Front-mount inter-cooler, Sard FPR, stock injectors, 3" DP back exhaust, nkg plat plugs.

I have one finally issue before I install my Power FC, from stock N374 ECU.
Is this stock ecu related: Under-throttle (open more then 20-30%) the fuel pressure drops while accelerating, Heating up engine of course. Would this be due to the Front mount and intake load being much greater then stock or an injector issue. (one injector can swivel on secondary rail). (32PSI raises 35-45PSI drops to 32 raises) throttle off steady again.

Only reason for this post here is because, will be installing POWER-fc with stock maf sensor. (Issue raised after putting on used turbo with front mount inter-cooler) and wondering if this is an ECU issue or an injector/spark/MAF issue.

 

I had checked into the MAF, adjustment of the screw does tend to lean out and richen mixture, as shown on a A/F gauge.
(Meaning: It will cause the tendency of the fuel pressure to stabilize under throttle.)
I would imagine the cooling issue will be solved my Drilling holes in my Thermostat as it holds until loaded, in which flow is insufficient.
(Meaning: Stock 82C thermostat opens and will supply flow but not enough to hold under boost once warm up temperature is achieved)

I could only think this is a tuning issue over a fuel or electronic mishap.

UPDATE:
Attempted adjusting both the FPR and the MAF - not very successful ended up just returning to original issue of bouncing needle and Ecu forcing fuel at higher rpms to accommodate.

Drilled 4 holes in the thermostat and it sits steady at 70C with ablility flow more at 82C


Will install my JDM FC3S S5 - FC BT-1 Style Apexi and see how that reacts to flow.