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

[Smaay]

i would get a wolfkatz fuel rail and new top feed injectors with a new regulator. make sure you have no fuel restrictions.

[Culpable04]

get a volt meter and check the map sensor, if that checks out, get a gauge and check fuel pressure.

[93vg30e]

yea i will check the map sensor tomorrow (i do have the full service manual) but found a fuel pressure regulator off a wrecked MR2 so i will pick that guy up and give it a shot, i have a feeling the regulator is whats at fault here.

[93vg30e]

hey all, well put in the new..er regulator the sound is gone but it still running almost as lean, tomorrow i will be rigging up an pressure gauge to measure input fuel pressure, from what i understand it should be in the 40PSI range. the engine still runs pretty smooth and only shows a code 54 for the intercooler circut (which i have looped)

for those of you that have a AEM uego what does it read with the engine off but ignition on?

thanks for the help and i will update you later on.

[RUNNIN-LOW]

hey there man i had that problem...i would say its the map sensor..but all cars are different...but that was why my car was running lean.. what i did was change the fuel filter, clean all my fuel injector and i even went as far as to do a engine pressure test, change out 2 fuel pumps.. at the end it was the map sensor that was screwing with me. maybe thats the case of your too.. some how i think the gen3 maps sensor or motors/some has the lean problem..i know a coupld gen3 mr2 that had the same leaning problems..but each was a different fix.