Adjustable FPR for stock 2003 return style rails?

[HalfCaseKustoms]

Is there an adjustable fuel pressure regulator out there for my 2003 6.0? I have factory return style fuel rails. I'm only reading 50 psi at the rails at idle and it drops when on the tgrottle. Brand new 255 pump in the tank. I figure it's the regulator that's the problem so I want to replace it with something adjustable if possible.

[BR3W CITY]

Most of the time we just keep the stock reg until we need fueling well-past what it can offer. A working stock FPR will adjust with vacuum if you needed that much more fuel (for boost), otherwise, your fueling needs are handled by injector duty cycle.

A stock truck FPR isn't expensive either.

[HalfCaseKustoms]

50psi is low correct? I'm having misfiring issues and it breaks up when getting on the throttle. I read somewhere that there is indeed a GM regulator that is somewhat adjustable?

[BR3W CITY]

Pull the vacuum line off the rail and see if the pressure changes. It should hold 55-65 (58 is "ideal"). 50 is low unless you have a Flex Fuel truck.

I'm not aware of an adjustable stock regulator. Most of us that need something more, and are already running return, just switch to a simple aftermarket rail/FPR. The stock one will adjust itself according to vacuum (or boost) up to a certain point. If you need to manual increase pressure, than your not supplying enough pressure from the pump.

I'd replace it with another stocker and see what happens. FWIW, turning an FPR up to increase fuel supply is a bandaid on this type of EFI; usually its better practice to use the fuel maps to scale it with duty cycle. Putting higher than desired pressure will make injectors harder to control (and rich) at low demand.