Ok guys, i never recieved directions on setting the pressure for this regulator. I have a holley 650 dp and a 355. I always thought the allen screw was for adjustment and the nut was for keeping the setting tight. How do I set the pressure on this regulator??? Do I use the nut for adjustment? If so clockwise/counter clockwise lowers pressure? I need help guys.

Zach

 

You hit it right on the head. I'm running the same reg and it's exactly as you describe.

 

Bigdreams, which way do i adjust the nut to lower the pressure? Or is it the screw, i am extremely confused over something quite simple. I have fuel all over my manifold and my fp gauge read 0 psi!!??! Is it the nut, or the screw for adjustment? If so which way lowers the pressure???

 

the screw goes in or out and the nut locks it down. i'd get a different fuel pressure guage if yours isn't working properly

 

So if the screw was all the way in, would that be the highest pressure setting? Or if the screw was all the way out would that be the highest pressure setting? Thanks, another thing, if I forgot to hook up my oil pressure sending unit, would that have anything to do with my fuel pump/pressure. The unit is in the top of the oil filter, but i forgot to plug it in. I just though of that now.

Zach

 

Screwing it further down decreases pressure while the farther you take it out increases pressure.

Where do you have your fuel pressure gauge hooked up?

If you have fuel all over your intake manifold, where is it leaking from? Is it a fuel line connection or from the carb? If from the carb, can you tell where it's coming from?

 

The leaking was coming out of both the needle and seat, front and back. And from what I can tell, fuel was coming out of the float bowl in the front. I'm not to sure though. I had the set screw almost all the way in and the fuel gauge read 0psi. I have the gauge screwed into the one of the "free" ports on the regulator. I'm at a loss. I listened for the fuel pump to prime but I couldn't really hear it, but there is fuel coming out???!! I need to have this car running by tomorrow and I have no clue what the problem is. The pump is stock in tank, tbi pump. IT worked fine when i had tbi and my old motor. Can somebody please help, I have no clue what to do.

Zach

 

The fuel line bringing fuel INTO the car from the tank should be in any SIDE port of the Mallory unit. The RETURN line should be connected to the BOTTOM of the Mallory unit. You should have a fuel line from any other port on the SIDE of the Mallory unit going into your carb. You should then cut into the fuel ine going into the carb, and put your pressure guage there, inline. Plug the other open ports on the Mallory unit.

Plug up that Oil Pressure Sending unit. The fuel pump may not run without it, as there is a direct positive flow from the battery to the in-tank pump that goes THROUGH the OPSU.

Loosen the nut, turn the screw to adjust pressure, tighten the nut back to hold the screw in place - the screw moves in and out of a seat in the bottom of the Mallory unit - it is actually adjusting how much fuel is RETURNED through the return line to the tank, rather than adjusting how much fuel is going into your carb. You want between 5 and 7 psi on your guage.

DO NOT connect a vacuum line to the Mallory unit - having such messed up my pressures and I never could get it right until I disconnected that vacuum line.

That's the way I have mine, and it's been just perfect for 6 months now - hope any of it helps.

 

Okay I have line setup a little different and need a little help, I have the return line on the bottom, inlet on the side coming from the tank on the left hand side of the regulator, and the line going to the carb is coming from the very front of the regulator and not the right side, this won't hurt anything will it? The right side is plugged. But what is the black fitting Ok the very back of the unit for? Could I screw my gauge into one of those free ports to see where my pressure is at? And if I'm correct you drive the screw into the regulator to reduce pressure, or take it out/ remove the scree to increase pressure correct?

 

Ttt

 

evilemokid
Jegs
Has the instruction sheet you can view.
Is there an arrow or " flow " anywhere on the ports?
Best I can say is the bottom port is for " return " .
In the thread camaronewbie says any side port should work for delivery to the carb.
See what he says about setting pressure.

Good luck
( edit )
IDK if you can use the ( 1/8" ? ) port for pressure gauge, I ** think ** that is for boost reference..?..

 

Well rel looked and I have my fuel line going to my carb on the bottom port. The front one set ad my return, and my left port as my supply. But I'm not sure how the adjusting screw goes. Do you screw it into the regulator to slow down the flow or turn it up?

 

Post #6 above.
Have a gauge? Where is it?
IMO run the lines as Mallory intends to be run

 

Post #8
For line use

 

The sheet says any 1 of the 4 ports can go to the carb, bottom port is for return.
Go to Jegs & check out the instruction sheet..
I would **think** diagram 3B would be the one to look at.An
Its free & no one will email or try to sell you something.

 

evilemokid
Get it set & running?

 

its been running just does seem like I have it adjusted correctly or can adjust it. Im waiting to get a longer fuel line and my regulator before I move stuff around but its working and running. I dont know how though

 

Gotcha!!
Best luck to ya!!