Installed a new SX fuel pressure regulator, but when the computer primes the fuel pump it doesn't register any fuel pressure on my fuel pressure gauge. I unhooked the return line and it was bone dry. I then undid the block off at the stock FPR location and fuel seeps out so i know fuel is flowing to the rail. The problem is the SX regulator is blocking the fuel and not allowing it to drain into the return line. I'm running a stock fuel filter, fuel pressure gauge tapped at the filter, AEM rail, -6AN inlets, and -4AN return. Anybody got any ideas as to what could be wrong? TIA

 

did you start turning on the adjusting screw? You probably did, someone I know didn't turn enough, it should resistance while turning the screw.

 

a regulator works by restricting flow to the return line. If the regulator is adjusted to a high pressure, you won't see much return fuel in the lines, if any, depending on the pump. Try adjusting the screw, see what happens. All else fails, it could be a fauly regulator.

 

I did try adjusting the SX FPR via the top mounted adjusting screw, but that didn't do much. Would it be ok to crank the motor in my current situation since i know there's fuel in the rail? The only thing that bothers me is that it's not registering any fuel pressure on my gauge. The car has been down for about a month, could the fuel just need more time to fully recirculate back to the tank?

 

Start it and see what happens. You won't hurt anything in a few seconds of running time. SX is a great regulator and their customer service is second to none. Don't be afraid to call them with a question

 

What I would do: (I use an SX regulator)
1) Check for leaks.
2) Turn the key on and off to have the pump prime the system about 5 times or until you feel adequate.
3) If possible, have someone look at the fuel gauge while doing this.
----The person should see pressure run through the gauge. Like said above, if the regulator is set high, the lines wont stay pressurized and the fuel will just drop back to atmospheric by going out the return line.
4) Try moving the gauge to the regulator itself, this will give a better idea what pressure is at the regulator--i think upstream (on the filter) you dont really get a good reading since the injectors are inbetween.
5) Tighten down the regulator adjustment screw until fuel pressure stays in the system, then loosen gradually till desired fuel pressure.
6) Call the customer support if nothing above helps.

 

Problem fixed itself. I dissassembled everything to check it out and everything was ok so i put it back together. While cranking the motor over for about a minute to prime my oil feed line, pressure built up in the rail and now i've got a normal 40psi after the fuel pump primes. The return line is still dry even with pressure in the rail, but i'm going to recheck it after i run the motor for a few seconds.
Thanks for the help!