well i got through half of my dyno session at jotech due to my fuel pressure dropping to 30 psi under boost.
the first pull on the dyno, the wideband showed a 15:1 air/fuel ratio!! i have been driving like that forever and have made several passes on the 1/4!
anyway, tony tried to richen up my AFC to get a better ratio, but noticed my fuel pressure drops to 30 psi under boost.

i can hear the pump going and fp is at 45 psi at idle.
both tony and kenny said it's my pump (walbro 255), but i've only had it for like 3 months
i took it out and looked at it yesterday and it looks fine and the filter looks normal.
i'm iffy on my b&m regulator tho because it doesn't adjust the fuel pressure very well when i try to turn the screw at the top.
could it be my regulator or do you think it's my pump?

thanks guys

 

Do you still have the stock regulator? Put that back on and see what that does.

would removing the vac line from your fpr solve anything either?

 

What size injectors?

 

I was going to say regulator as well. Usually when the pump is bad it won't hold pressure, but will rise a bit before falling. When it just drops, the regulator is usually the culprit.

 

Since the pressure is OK at idle & only dropping under boost, conceivable that you have insufficient flow to be able to maintain the pressure under the increased flow requirements at boost.
Make sure you have adequate conductance in your supply line & that the tank is venting.

 

my fuel pressure is just falling constantly
i have 450cc injectors running the hack,
tony had to richen the SAFC to -22% and it's still lean
i'm gonna put the new pump in and have then strap the car down on the dyno again to see what's up
i'll update this post