OK, I HAVE A SK RACING 48. i was running excessive fuel pressure from my walbro, i had hooked up a switch to see if i had any fuel leaks, so the car wasnt cranking, and i wasnt pushing the thottle. well any way with excessive fuel pressure, instead of the fuel going out my return on the carb, it just poored out the throats, i didnt see where, but it was all over....


P.S. it was not only at high pressures, it leaked out at only 3 psi. im using a mallory 4309 regulator, and i was using a walbro 255, but i switched to a purolator...

im in a hurry, and this has been covered, im sorry just tell me, and i will search when i get bacl from work, but i wanted to get this up as soon as i could, incase it were something more. thanks.

 

You don't say which Walbro you are running, but my first guess is it is too much flow for the stock return line. You may need to plumb in a larger return line, or go to a smaller fuel pump.

 

time for a new needle valve possibly, if the fuel pressure is really at 3 psi(at the carb) where is your fuel pressure guage mounted? the return line is going out the bottom of the regulator , right?
the pump is fine, your problem is elsewhere

 

i don't want to hijack the thread and I don't know if i should start a new thread about the SAME issue...?

I have the same regulator 4309 Mallory with a Holley fuel pump, currently running a stock nikki and it's pouring out the carb vs going back to the tank on the return. I have the fuel pressure guage mounted directly coming out of the regulator off one of the feed ports. I can't get the pressure down no matter which way I turn the screw... It's stuck at 14-15 psi...??? I have a 1/2 feed with a 3/8 return and the return is plumbed out of the bottom port.

 

I'm not positive, but I believe you need a bigger return line. If the return line doesn't flow enough fuel, your pressure will be uncontrollable.

 

i said it was a 255lph pup, and i dont have a hose on the return of my carb, and nothing came out

my gauge isnt actually mounted yet, its hookd up, but its not mounted. heres the deal, i had the walbro on, and i hit 3 psi but then it climbed, cause my return isnt large enough. thats why i swapped out to my weaker pump.

i think my return is horizontal...and i do have quite a bit of line between the guage, and the isolator??

if i concluded it were my needle valve, how much would that cost? and could you send it with the oil return line??


i havent tried it with my weaker pump yet actually... do you think it only did that cause of the excessive fuel?? but if thats so, why didnt the fuel that wasnt utilized by the carb, go out the return?


EDIT: ive looked in my manual, and i know what the needle valve is, is there any way to check it to see if its good or not??

 

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if the 3/8 return line is going back into the gas tank without any restrictions then your fpr is bad.. or you have a problem with your needle valve in the carb

a way for you guys to test if the return line is the problem is to run the return line from the fpr into a gas can .. this will insure no restrictions on the return.. turn the fuel pump on and see what happens.. no more flooding results in rectricted return system.. if the problem presists your problem is in the carb itself or the fpr....

 

put the weak pump on to test the carb or try the fuel test i mentioned above and see what happens
there is a way to check the needle valve but you need to check it with 4 psi, or it will leak, even if its a new one..

 

Did the gascan catch test, nothing is coming outof the return port. My FPR = no good. I did buy it used form a forum member. Ohhhh well. Thanks.

 

Can the regulator be rebuilt or do I have to spring for another one... Even with the screw ALL the way out it only goes down to 12psi...?

 

im pretty sure you can buy rebuild kits depending on the moddle, if not, i may have an old holley fpr ill let go for pretty cheap.

 

that sucks.. its better to buy a new fpr, that way you know its good.. go for the mallory #4309, with cheese

 

Hey perfect circle, thanks for the offer but I just spent lots of time I don't have routing an entire new fuel system with aluminum line and SS braided... I'd prefer to swap in the same exact part so nothing has to be shortened or lengthened or re-fit yadda yadda... I picked up a new one from Jegs, it should be here Friday.

Anyone want to buy a Mallory 4309 FPR...???