Too much fuel pressure?

[03BlkZ]

Hello, I am having a difficult time getting my carb set right. I'm wondering if I am running too much fuel pressure. I have an AC Delco mechanical fuel pump and my inline gauge shows to be running between 7 and 8 psi of pressure. I am running the summit M08600VS 600 CFM carb which is basically a Holley. The trucknis running rich and none of the adjustments seem to help. My idle adjustment screws don't seem to make a difference when adjusting and watching vacuum. Also I have fuel leaking from the throttle shaft. I have read that edelbrock carbs require less pressure so I was wondering if my summit carb does as well.

[jocko]

5-6 psi is recommended for most stock systems, incl stock replacements like the edelbrock/summit, etc. You can install a pressure regulator inline with the pump to control it - but, generally speaking, any mech pump usually delivers the required 5-6 psi - might be possible the gauge is off a bit. If you know you have a throttle shaft leak, highly recommend addressing that before trying to troubleshoot other things.

[jocko]

Found this from Summit on the ol interweb, maybe it will help:

[RustyPile]

I'm not familiar with that particular carburetor.. If it has a power valve like a Holly, it's possible the diaphragm is ruptured.. Have you checked he float level?? It could be too high.. What about the main jets?? Are they too big??.. No response from the idle mixture adjustments could be because the throttle butterflies are open beyond the transfer passage..

[03BlkZ]

Originally Posted by RustyPile

I'm not familiar with that particular carburetor.. If it has a power valve like a Holly, it's possible the diaphragm is ruptured.. Have you checked he float level?? It could be too high.. What about the main jets?? Are they too big??.. No response from the idle mixture adjustments could be because the throttle butterflies are open beyond the transfer passage..

I have tried to adjust the floats but im having g a hard time getting them to react to my adjustments. This carb has sight windows and says to adjust to half way up the sight window. The rear float is about right but I can't seem to get the forward to come up. It's almost at the bottom of the sight window. I have not checked the power valve or the jets yet. I'm still learning on carbs sonits taking me a bit.

[03BlkZ]

Originally Posted by jocko

Found this from Summit on the ol interweb, maybe it will help:

Thanks! Looks like I may need to get a regulator and give it a try.

[Steeveedee]

Fuel leaking from the throttle shaft means it is flooding.

[03BlkZ]

Originally Posted by Steeveedee

Fuel leaking from the throttle shaft means it is flooding.

That was my thought. I will try a regulator and see if it helps.

[OregonNed]

Just my experience - cured mine with an Edelbrock pump for my Edelbrock carbs - did the trick for me.

[firedemon]

a holley carb will take 9psi no problem not sure with copy cat type but i would think it would be very close . it sounds like it is flooding if its leaking by the throttle shaft . it wont adjust no matter what you do if you dont solve this first . usually i like to set my float level so the fuel just barely spills out where the sight glass is when the glass is not in the carb . halfway up the glass seems too much fuel in the bowl .

['68OrangeSunshine]

Originally Posted by OregonNed

Just my experience - cured mine with an Edelbrock pump for my Edelbrock carbs - did the trick for me.

Was your Edelbrock pump electric or mechanical?