Fuel Pressure Regulator What PSI Should I set it at?

[petey-pablo]

Hello I was wondering if anyone new what was the best PSI to set my Fuel Pressure Regulator at? I think my motor is getting too much fuel it back fires and wants to stall when I punch it very hard start when cold sometimes it even catches fire I am running a Proform 750 cfm, 4-Barrel Race Series Carburetor and a Holley Blue Electric Fuel Pump & Holley Fuel Pressure Regulator, MSD Pro-Billet Distributor. My motor is a 454BB with a Mild Cam Not sure what cam I have.. I also have a Fuel Pressure Gauge and I am currently at 7PSI.. Truck ran fine before I swaped out the old Fuel Pressure Regulator so my guess would be I didn't set it right since it didn't have a Fuel Pressure Gauge I don't know what it was set at I just went by looks, I tried to match it up as best as I could..
Thanks Pablo

[Tx Firefighter]

Popping fire back through the carb is timing mis-adjustment.

[cdowns]

depends on your carb most are between 5-7lbs of pressure,you do have a gauge on the regulator ?

i agree the spiting up thru carb is normally a timing issue

[truckdude239]

5-8 psi

[rico7769]

play with 5-7 and check the carb specs. I run 7.5 with no issues. Any higher and I get flooding issues. Backfires are generally related to timing though. My two cents

[70duramax]

backfire through carb = timing issue
backfire through the pipes = fuel issue

[QKENUF4U]

ive always heard/read 7psi max.....

[67chevemall]

I think the stock mech fuel pump is 4.5 ?

[petey-pablo]

Aww you guys are awsome I would have never guessed it was timing issue, Because I have never messed with the dizzy.... I went out and tried to fire it up and poof it blew backfired and set fire again then I checked the dizzy and it was loose what do you know so I turned it just alittle and wow it started rite up thanks again guys.........Now I am off to the mechanic so he can set my timing.......

[Amber1982]

Hi there! On the same topic, different concern... I have recently converted the fuel pump on my 77 GMC Vandura to an electric. Looking at the pressure specs, I wonder if I just bought into a useless fuel pump! The clerk at Autozone sold me one that is rated for 2-4 PSI and tried to send me off with a regulator that only went up to 4 as well.
The pump did get the van running, and able to be driven to work, but I won't feel comfortable that it is done and ready for a real adventure until I put the regulator in.
I am pretty new to this van, it has been a lot of fun and learning for me!
Would it be wise to get a stronger pump to at least have on hand should the current one crap out while I am in the middle of nowhere?

[geezer#99]

Tee a fuel pressure gauge into the fuel line to the carb and see what the pressure is when it’s running.
I’ve never seen an electric pump rated so low.
4 psi won’t hurt anything.
Your carb likely won’t handle more than 6 psi anyway.
The regulator might of been a return style. Highly recommended for an electric pump. They like to heat up and quit if they’re deadheaded.
What made you think you needed an electric pump anyway?

[Amber1982]

What made you think you needed an electric pump anyway?[/QUOTE]
Posted via Mobile Device

The mechanical pump went out- in replacing it, the cam arm was stuck down and could not be pulled up. Once I got it loosened enough to at least spin a little, it felt slightly bent.

[mike16]

back firing through the carb is a lean fuel condition. It may be timing but in the context of a fuel related issue its an indication of a lean condition.

and according to .......Doug Roe's Rochester carburetors, published way back in 1981 by HP Books....... on pg 116 it says between 4 and 6 psi. It also states several times that pressure should never exceed 6 psi and can be operated down ward to 2 psi under rough terrain conditions.

['68OrangeSunshine]

Edelbrocks like 5.5 PSI.
I know nothing about Proforms.