I'm in the process of tuning but think my fuel pressure may be a problem. Have a Vortec 350 with HSR, 30# Accel injectors, holley fuel rails with stock non-adjustable regulator. Racetronix 255 fuel pump which is fairly new, newer fuel filter. At idle my fuel pressure is about 28psi and doesn't move much when the throttle is snapped. Would this be regulator related? Previously had a AcDelco fuel pump with same engine, had same results. First pic is engine idle vacuum and second is the idle fuel pressure.

 

What regulator are u using u want to set fuel pressure with no vac hooked up motor running then set to 43-45 psi then hook up the vac line to it, it will drop in pressure when vac is hooked up once u give throttle it should jump up to the 42-45 psi if not then u have a fuel problem

 

Stock FP is around 43 psi w no vac; 37ish w full vac applied to FPR.

"Snap throttle" isn't a good way to test anything. Engines react differently to that. Check FP by disconnecting the vac line to the FPR. FP should go up several PSI.

You DEFINITLEY have a FP problem if that gauge is accurate.

If in fact you have that low of FP, I'd suspect incorrect line hookup. Correct plumbing is something like: pressure line from pump to one end of one fuel rail; "jumper" line from other end of that rail, to one end of other rail; FPR in opposite end of 2nd rail from the "jumper" line; return line to regulator "waste" or "return" output. Sounds lo me like you might have the 2 lines backwards.

 

Sofa kingdom not saying he should snap throttle but if he holds the the throttle back he will see that it will raise up to 43-45 psi or w.e he set it to

 

Thanks for the replies guys. The regulator is a stock non-adjustable Holley one that comes on their fuel rails for the stealth ram. I did have to convert the the lines in the engine bay to -6an and tied those into the fuel rail. Pretty sure I put the right lines in the right places.

Someone said since the engine had so much vacuum at idle and I have large injectors, that the pressure would be lower. Kinda made sense but I'm thinking I really need an adjustable regulator here.

When I disconnect the vacuum from regulator, pressure goes up to about 38-40 psi.

 

Ok so since ur using the holly non adjustable one that mounts to the rail take that's out and go get urself a aeromotive regulator or u can use the kirban one that mounts to the rail as well don't know the exact part number for it but there are tons of guys on here that use it