JIMMY91

A friend of mine just replaced his fpr on his camaro 350 carbed engine,and he brought to my attention the diagram holley has for the install of the 12-803 . The regulator itself has 3 ports ,1 on each side going out clearly marked out ,and the bottom port is marked in,pretty simple we all know.But the instructions he showed for that particular regulator states that the bottom port is for the return line to the tank and the side ports are fuel in ,and fuel out. How many of you noticed this before? I have the same regulator and have mine plumbed with the bottom port as fuel going in ,and 1 side port to carb and the other side port as a return to the tank,I even checked the Holley site and the instructions say the same as the paper instructions. Did Holley change things up ? This is a first for me ,never noticed this before.

86sc5

iTrader: (1)

I have mine fuel in bottom port. 1 side port to carb. Other side port plugged. those instructions are F'd up. I have a return on my pump.

JIMMY91

I agree.

Apeiron

Sounds right if you were going to connect it as a bypass regulator.

JIMMY91

Are you referring to the Holley instructions ? Using the bottom as a return and the 2 sides as fuel in and fuel out to carb?

Apeiron

Yes, check the instructions: http://www.holley.com/data/Products/...199R7914-3.pdf

Page 3 has 3 figures. Figure 1 is for the deadhead regulators, the 12-803, 12-501, 12-804 and 12-500. Figures 2a and 2b are for the return regulator, 12-803BP. It's explained at the bottom of Page 2.

JIMMY91

Thanks,I just realized he also has the reulator that comes with the holley blues,12-802. The 12-802bp is the lower pressure regulator 4-7 psi...we both have the holley blue that is 14 psi...Do you think I should plumb his regulator as in 2a or should I plumb it as mine, which is fuel in through the bottom port ,and one side port going to tank and the other side port going to carb. Does it really make a difference ,I have had no problems with mine at all set up my way...

Apeiron

The significant difference isn't the pressure, it's whether it's a bypass regulator or not. That's the "BP" suffix on the part number. If you have a "BP" regulator, you need to use Figure 2. If it's a non-"BP" regulator, you need to use Figure 1.

JIMMY91

Thanks Apeiron, All this time I have been running standard regulator when I thought I was running the bypass style. I actually have the original box it came in and it was marked as a bypass reg ,and instead the 1 in the box was a standard reg,I never looked when I installed it. Thanks to my buddy and you I now realized it...It was like dead heading the pump,now I know why I killed 2 factory intank pumps a few yrs back...Glad I did not toast the holley it's amazing the car ran so dam good ...Thanks again..............

Apeiron

How do you know it's a standard regulator?

The Holley pump has an internal bypass inside, so you can use it with a deadhead regulator. You'd find things would run a lot quieter and cooler with a return regulator, though.

JIMMY91

The non by pass regulator would be considered stand regulator #12-803...Like you said the bp was the one I wanted. Just got back from the speed shop ,got the bp style.Even got it for free since I showed the box to them and they realized it was packaged wrong. That was over 3 years ago.

marine68

i have the red holley elec pump and i am using the 803bp regulator and the most pressure i can get is 4psi. is that because of the return line to the tank. maybe i don't need the return but i heard it cools the pump or something.

Apeiron

You don't need a regulator with a red pump. It has a 7 PSI bypass spring in it, so the most pressure you'll ever have in the line at the pump exit is 7 PSI. With pressure drop in the line to the front, you'll have less at the engine.

marine68

but i/m using the return line that goes to tank. should i remove the regulator and the return line and plug it at the tank

Apeiron

You don't need a return line with a red pump either. Try pinching off the return line and see what happens to your pressure.

marine68

o.k. it spiked to 6psi. instead of going to all the trouble of removing the regulator and nice alum return line could i just remove the spring from the regulator

Apeiron

Up to 6? is this a new regulator or an old one?

If you removed the spring from the regulator you'd just be sending all your fuel back to the tank.

marine68

it is only a couple months old, the red fuel pumps max pressure is 7 psi