brandon davis

iTrader: (3)

My 45dcoe weber is pouring fuel out of the 3/4 in hole behind the velocity stacks. I have my relay jumpered, NO engine fuse, and the key in the on position. Shouldnt the FPR (4309) return the extra fuel. My guage off the FPR was reading 8 psi I adjusted it down to 3-4 psi.

Has anyone had this happen to them on the FI to carby swap?

Rx-7Doctor

iTrader: (13)

You may have damaged the needle seat with too much pressure or its stuck and not shutting off now.
The return system only allows fuel to return once the needle seat closes.

Rx-7Doctor

iTrader: (13)

Brandon,
I also changed your thread title. The generic "Help" title don't inform anyone what you are looking for unless they go into your thread. Also a good title helps for future uage when using the search function.

brandon davis

iTrader: (3)

I also didnt have the vaccum nipple uncovered.

Siraniko

iTrader: (13)

I had similar issues with a 4309 (ask DoLuck)...thats using MSD F/I fuel pump. I had to use a modded holley 1-4 psi regulator for a return and it worked fine.

brandon davis

iTrader: (3)

So you still had the an FI fuel pump! And for the return you used a holly?

Ive been told that the stock SE pump will work fine with a mallory 4309. I am thinking of just ditching the SE FI pump and using a good carby pump? Any other quick solutions i might be missing? If not what kinda carby pump suggestions does anyome have?

Siraniko

iTrader: (13)

I ran a MSD F/I in my 48 IDA (with plans to do blow-thru upgrade on a 13-B streetport). The crappy 4309 cant keep the flow below 9PSI even with a return. Out of desperation, I just used an old holley regulator with a return and added a IDA fuel jet on the stock return line to regulate teh flow back to tank/prevent fuel starvation.

A month later, I went back to my holley red.

PS: btw, the main fuel line is 1/2" . if you get a holley pump, find a 3/8-1/2 fitting.

NoPis10

iTrader: (29)

I was running a Carter fuel pump with a 4309 set at 5psi on my streetported 13B with Mikuni carbs with no problems.
As for the 4309, many people down here are running them with no problems on boosted motors, I have one that I will use on my blowthru system that I am putting together.
L8R

brandon davis

iTrader: (3)

Update. Now fuel is coming outs the velocity stacks. With no relay jumper, no engine fuse installed only when turning the engine over. I am so close to starting this project.

brandon davis

iTrader: (3)

While cranking the engine over i adjusted the FPR guage to 4 PSI. Ill check the needle valve, and float level. See if that eliminates the fuel leaking. The troubleshooting guide says needle vlave, leaking or damaged floats, incorrect float level, or excessive sediment in fuel.

brandon davis

iTrader: (3)

I have the weber manual. And under the float adjustment picture it shows what everything is but doesnt state how to adjust. I am thinking of bending the short adjustment tab down to prevent the tab from unseating the needle valve soo much is this right?

trochoid

iTrader: (6)

Follow the Weber float adjustments to the letter. Have you replaced the needles and seats? If you're fuel pressure is in line and it's still flooding, replace them.

Siraniko

iTrader: (13)

According to Robert that years ago, the 4309 were sold with 2 types of spring: soft and hard. I cant remember which one but at any rate, having the wrong spring is the cause.

brandon davis

iTrader: (3)

Well I adjusted the the floats as per the weber manual. No more flodding, i also inspected the needle valve on the carb and it was perfect. I dont have the leaking at all anymore. I think i need to readjust it though cuz i have spark and about 4 psi on FPR guage but i think im not getting enough fuel now. I guess the needle vlave is very very sensitive. HUH???