3sgte swap done, running lean.... Options

[93vg30e]

Hey all,

well i have finished the swap and it runs quite well with only one flaw it is running super lean. I installed a wideband AEM Uego gauge and it is showing about 17.8-18.8 at idle and then off the guage under power. i have verifed the lean condition by pulling the 02 sensor and it was starting to show white. The exhaust is completely built 3 inch turbo back with muffler and resonator.

info
3rd gen 3sgte
running walbro 255lph pump
idles at about 15in-hg of vacuum
still has old regular fuel from 8 months ago

the fuel pressure regulator has a odd sound like a washing machine filling up with water when the pump is on but the engine is not running, is this normal???

Things i have done to try and solve this

-check for restriction in fuel filter (tests fine)
-turn on pump to check fuel flow after filter with line off (tests fine)
-pull all plugs/change and found no differences between the cylinders
-triple check all vacuum lines, and plug and pinch off while engine is running (looks good)
-pull fuel pressure regulator to make sure fuel flow hits the end of the rail (shoot out of port)
-unplug 02 sensor does nothing (but i understand that the ECU has a backup map in so it really should not matter)

things it does
-if i unplug the boost sensor (map sensor) (the vacuum line running to it) it engine will run sickly rich and almost stall
-if i clamp the fuel return line it also will run richer...

possible things it might be but i have no idea....
-fuel pressure regulator?? it seems to run the same and have same fuel ratio even when the vacuum line is unplugged to it
-fuel pump, maby i got a weak one???

thanks for any help, i have spent so many hours on this car and am very excited to drive it when its done...

This post has been edited by 93vg30e: Jun 3, 2010 - 10:21 PM