here's my fuel setup right now:

vortech FMU 4:1
36# (370 cc) injectors
walbro 255 lph fuel pump
SAFC

now my problem is, i just hooked up a guage yesterday and saw that i am running about 65 psi at idle. thats not right. when i start to transition into boost, my pressure starts to lower itself to about 40-55 about. i just changed the fuel filter about 2 months ago so i am unclear how this could be happening. i checked my pressure about a year or so ago and it was at about 50-55 where it should be for stock injectors. i also have another problem. whenever i initially touch the gas, either coming off of a stop, or changing into any gear, the AFR guage shoots to lean and the car hesitates/stalls for about 1-2 seconds. the car finally catches itself and starts to drive normally. this is a huge problem, especially on an incline because the car does not want to do anything, the rpms don't rise but the vacuum does. does anyone have or have had these symptoms? Could it maybe be the fuel pump? Bad SAFC? this problem is really starting to irritate me because it forces me to drive like a grandma...

Thanks guys

It's because your turbo is acting like a restriction, increasing the vacuum, until it's actually helping along the air. It sounds like you don't have the restrictor inline to your sfmu, if you do and you are using the bleeder screw, you need the check valve on it. The trick is to keep the vacuum in the sfmu to never go below that of when you idle, and you actually want it to rise just a little at part throttle, unlike stock, because the turbo reaches a point where it's helping along extra air even though you're not making a positive pressure yet.

Joel Baldridge, ASE Certified Master Technician, Audi Certified Expert Technician

i'm not using the SFMU. I have just the FMU in there now until i put my new SFMU and 440's in there. What could cause my fuel pressure to rise like that over just a year. i didn't do anything and i thought we couldn't adjust our static fuel pressure unless we have a regulator or SFMU? Also what could be causing this nasty stalling/hesitation when i first apply gas?

Oh I'm sorry, I read SAFC as SFMU.

A restriction in the return line increases fuel pressure, aka the fmu. A clogged fuel filter would lower top fuel pressure.

I would try putting a check valve inline before you FMU. MAKE CERTAIN you install it so it will still see boost.

Joel Baldridge, ASE Certified Master Technician, Audi Certified Expert Technician

just ditch the FMU and get somethign adjustable quickly!!!!!

-MIKE-

Stroked 2.2L

Whoa..65psi at idle with 370cc injectors, that's way too rich. You should be at like 15-18psi @ idle I think. You should really look into ditching the SAFC and get a SMFU then use the bleed valve to dial in the right fuel curve. I idle fine with 310cc @ 20psi of fuel with NO SAFC, others have to use the SAFC to get it to idle right. Either way you need to get your FP right and then go from there.

Alvin

http://www.cardomain.com/id/96rst

yeah, like i said earlier, i have the sfmu and 440's but it has been so so so hot here in st. louis, that i haven't really had the desire to get out there and put them in. plus i still have to buy all the fittings and lines and figure out which goes where, and that seems like SUCH a freakin headache. I am not looking forward to installing these pieces...

thanks for the help so far guys