So you stumbled in from the gs section to bump a year old thread with bad logic? Nice!

I can agree with confirming proper pressure, but your fuel volume theory in this situation sucks. A setup at this level is more than adequate for what the turbos are capable of flowing power wise. You state that you can have the pressure but lack volume. NEVER will this happen with a stock fuel system on a stock twins car. Your acceleration or throttle opening rate enrichment theory sucks here too for the same reason, stock ecu can manage on this one even on small singles for the most part. There was so much wrong with this thread in the first place. Swap was supposedly done by a professional shop where the OP worked, yet the harness was made way too long, plugs gapped way way too tight, as well as a couple other red flags

 

I just noticed the OP said they have a FMI. I think he means FMU and could be the problem.
is it a rising rate one? you might be dealing out too much fuel pressure. was the base fuel pressure adjusted correctly? I would look there first.