What is the correct fuel rail pressure to run on my setup... Aeromotive fpr, 60# injectors, and 9 psi. My old tuner / shop guy said I shouldn't ever run under 65 psi on my fuel rail but I've been doing some reaseach. ( only finding alot! Of foul things he's done to my truck). Maybe this is why at 2000 rpms the truck sputters alittle and the fuel pressure goes haywire...

 

You can pretty much run whatever pressure you want. As long as the injectors tables follow them correctly for flow. you also want your FPR to be referenced to you boost.

What does haywire mean? drops? sounds like regulator problems.

I would start at 58 psi probably, because that is likely what your injector tables reflect. And small psi changes will fall into the VE table

 

Assuming your reg is a boost reference reg set your idle psi to 58-60 psi and you'll be good to go.

 

^^^ this but it all depends on how your tuned really. if your tuner tuned your fuel trims to 65 psi and you go down to 58 psi you will probably run lean.

 

Good to go, unless the tuner set up the tune to reflect what the injectors flow at 65 psi. After you eliminate the regulator as a problem, you should go to an experienced, reputable tuner.

 

I type so slowly.

 

Is there any problem setting the regulator up to 45-50 psi at idle as long as it it is tuned for it? Reason i ask is because injectors flow more at higher fuel pressure but fuel pump flows a lot less. So with 58psi base pressure and 12lbs of boost you are seeing fuel pressure of 70psi but with a base pressure of 50psi and 12psi of boost you are at 62psi where the fuel pump can flow a lot more.

 

^^no, thunder550 IIRC lowered fuel pressure several lbs, IDC went up 10% or so and he had better luck like that. i cant remember the details

 

adjusting your regulator isn't going to affect your fuel pump . only way to adjust your fuel pump pressure is though voltage right?? your pumps are like a on and off switch and unless you give it less or more voltage it should act the same no matter what the regulator is set at , please correct me if im wrong ??

 

Thunder550 had 96lbs/hr injectors. He did drop the pressure to 43 and tuned for it and it ran great. Most injectors are rated at 43lbs/hr and that's where they're designed to run. Increasing fuel pressure makes them act bigger, but puts more load on the fuel pumps. If your injectors are big enough, run 43psi boost referenced and adjust the tune accordingly and you will have a happy fuel system.