I just got my new LS/VTEC setup started for the first time in 8 months. It was running like crap so I checked the fuel pressure - 110 psi at idle! Here is how I have my fuel system set up:

stock fuel filter-->stock fuel line-->STR fuel rail w/ RC 440cc--> -6an line-->SX fuel regulator (p/n 15404)--> -6an line-->Vortech 12:1 FMU-->stock rubber return line.

I have all the vacuum lines routed the right way, I tried to turn the screw in the SX all the way out & it did nothing. Next I disconnected the -6 line which goes from the bottom of the SX to the inlet of the FMU and put it in an empty soda bottle, had somebody start the car --> 40 psi..at idle w/ FMU disconnected. Ok, so the 100+ psi at idle problem is coming from the FMU, right. So I take off the FMU cap and the little metal cylinder inside is popped up pretty high, compare this to my bro's FMU and the little metal cylinder is not popped up at all. Is the FMU broken? Is it possible that the -6 line flows too much fuel for the FMU, causing it to break? Has anyone hooked up an SX regulator w/ an FMU and had the same problems? Sorry this is soo long but any help will be appreciated, thanks..

The fuel management is the infamous 440cc, 12:1 FMU, V-AFC, 255 lph Holly in-tank combo by the way.

 

why are you even using the fmu? you have a vafc and the 440s. just put on a stock one and go from there. you would be running ridiculously rich with a 12:1 fmu and 440s.

 

sounds like the winning solution! pull the FMU and hit the dyno for some tuning. then kick *** around town.

 

Hey Jay,
Its Vadim, this happened before on a couple of setups that I have built. Give me a call on my cell phone and I will tell you how to fix it. I will im my cell number to you. I guess you took the im feature off your profile. Either way, its hard to explain it over the board. Get my number from somebody or im me.
EVIL