Fuel pressure regulator

[dirtwarrior17]

Which way do you screw it to bring the psi down?

Does more area inside the regulator = more psi or less psi?

I am trying to run my 45 psi pump with the holley tbi and adjustable regulator and need to get this figured out because i just blew both my injectors and don't want to go through the same thing with the new ones.

 

[dave_90_blazer]

Which way do you screw it to bring the psi down?

Does more area inside the regulator = more psi or less psi?

I am trying to run my 45 psi pump with the holley tbi and adjustable regulator and need to get this figured out because i just blew both my injectors and don't want to go through the same thing with the new ones.

the psi goes uo the farther in you have the screw, it is best to back it out most of the way, then power up the pump, then slowly turn the screw in till its at the psi you want

 

[dirtwarrior17]

correct me if i'm wrong but wouldn't that let more fuel in? I know that is the general rule and what holley told me but with more space inside the regulator doesn't that mean more fuel to the injectors?

Your saying that compressing the spring equals more psi right?

 

[Storm Trooper]

What regulator? Heres mine - Mallory
Yes, when you screw it in (CW) it increases the pressure.
CCW decreases pressure. Get a pressure gauge and hook it in the outlet to set the PSI. Mine has 4 - ports so I have one with a valve that I can hook up a gauge to set it or hook up a line to pump gas to someone in need.

 

[Thunder]

Might want to use GM injectors and a stock 454 TB. Holleys are Crap.(along with the rest of their prouducts) Get used to blowing them.

 

[4X4HIGH]

Ok, to start off with i don't think you can run that high of a psi pump with the tbi regulator because what is going to happen is the psi of the pump will overcome the tension of the regulator spring no matter where you have it adjusted which means that you will have way too much fuel pressure.

If you study the regulator assembly carefully you will find that the more tension you put on the spring the more fuel pressure you will have.

 

[dirtwarrior17]

what would you suggest then? another inline regulator?

 

[4X4HIGH]

A different fuel pump which doesn't put out that much PSI. It's the only way you're gonna make it work. You need a pump that doesn't put out more than 20 PSI. The factory pump puts out between 11-14 PSI.

 

[southernspeed]

My Jet reg (that replaces the stock TBI one needs the screw underneath turning counter clockwise which pushes the the spring tighter against the diaphram which increases fuel pressure (reg is after the injectors so restricting return flow makes more pressure at the injecters).
But as 4x4HIGH says, I recon you need a lower pressure pump. I'm using a Turbo City 15psi pump (that's what they advertise it as) and by adjusting my Jet FPR I ranged between 7 and 22 PSI. (although my new Summit inline fuel gauge read between 7 to 9 psi all the time!). But using my Snap On fuel pressure guage I set it to 13.5psi. All seems well at the moment but I'm only driving it gently while I break the motor in. I may go for one of those vaccum type FPRs.