Carb problem... is it fuel pressure?

OonDeanisS · Jun 19, 2005

Its been a while since i started my car because the dash has been out, and i started it a few times, then let it sit a few days. Next time i tried to start it, it didnt start, so i looked under the hood, and my lower intake was a pool oof gas. Turns out gasoline is spraying out of the tube that runs along the front of the carb that goes straight up the side to the top. If i turn off my fuel pump it doesnt do anything. Is it the carb? the fuel pump? FPR? please help me i need my car to get to work.

txstang84 · Jun 19, 2005

if all your lines are on tight, then the floats might be stuck down allowing gas to keep pouring into the bowls and eventually out of the air horn...or the needle adjustment on the front of the bowl may be leaking, i know where you're coming from, i've had nothing but bad luck with holley's...

just ck to make sure everythings tight, and see if that helps-don't suppose you've got any pix do ya?

Dark Knight · Jun 19, 2005

check the needle valve for dirt too

MrKwik · Jun 19, 2005

Dark Knight said:
check the needle valve for dirt too

I second that. Holly carbs are real good about sticking the needle valve open. Do you have a good fuel filter installed? If not, get one.

OonDeanisS · Jun 21, 2005

I can get pics, but i dont know how to post them, and i dont know what a needle valve is... sorry

PuterAmI · Jun 22, 2005

OonDeanisS said:
i dont know what a needle valve is... sorry

Time to go to school.

http://www.holley.com/HiOctn/TechServ/TechInfo/FMCTech.html

OonDeanisS · Jun 23, 2005

well i think that says that the needle valve is the screw going into the side, but mine has one of those on both sides... Are they both needle valves?

PuterAmI · Jun 23, 2005

What MrKwik meant is mentioning is the needle/seat assembly. It is the part of the inlet of the fuel bowl that determines the fuel bowl level. They can stick allowing the fuel bowl to runneth over.

What you are describing is the idle adjustment needles. They adjust the lean/rich mixture at idle.

OonDeanisS · Jun 24, 2005

so where on the carb should i look for the needle/seat assembly? thanks for your patience everyone... someday i'll be good with carbs too.

PuterAmI · Jun 24, 2005

Inside the bowl.

http://www.holley.com/HiOctn/TechServ/TechInfo/P218A.html

OonDeanisS · Jun 24, 2005

from the picture, it looks like the valve pin is inside the box on the front of the carb, is it not?

PuterAmI · Jun 24, 2005

valve pin = needle/seat
box = bowl

Yes.

OonDeanisS · Jun 25, 2005

so i have to take the bowl off the carb to see whats inside it right? how do i do that? when i looked at it, i only saw one flathead bolt on the top of it.

PuterAmI · Jun 25, 2005

There should be 4 screws on the front of the bowl.

I highly suggest that you get a book on how to rebuild Holley carburetors at any bookstore.

OonDeanisS · Jun 26, 2005

ok i took the bowl off, and ruined the old gasket, of course. Now im stuck because i dont know where to get a new gasket, because autozone told me they dont have one. The pin valve isn't stuck open, and i cleaned the whole bowl with throttle body cleaner once it was off the carb. I see how the fuel could be filling up the bowl and going out the air-horn, but i dont get why the float wouldnt close up the valve, if its not stuck. Could it be too much fuel pressure? I think it started to come out the airhorn when it got around 4psi.

PuterAmI · Jun 26, 2005

My Autozone has them. So does O'Reilly's. I just threw a kit at mine last weekend.
Autozone orders Holley parts for me.

A Holley likes ~6PSI. The needle could have had some dirt so that it was not sealing properly. I just replace them.

OonDeanisS · Jun 27, 2005

the needles? How do i know what model my carb is? it has 2350 engraved in the side but it has a "holley remanufactured" sticker that says 2682. now that its apart, i see that the needle in the bowl inlet only sticks up, even when the float drops, but only sometimes, and it comes down if i tap the bowl. I think thats just cuz its dry metal.

PuterAmI · Jun 27, 2005

The "list" number is usually stamped into the air horn. You can then take that number and look it up from the Numerical listing on Holley's website.

MrKwik · Jun 27, 2005

OonDeanisS said:
i dont know what a needle valve is... sorry

Then your gonna hate owning a Holly

Anyway...no need to pull the float bowl off to get to the needle valve assembly, don't know who told you to do that. There is a big flat head screw looking thing with a jamnut on the top of each bowl. Just loosen the screw and back the nut out to remove the needle valve. Look at the tip of the needle very closely and see if there is any kind, AND I MEAN ANY KIND, of debris on the tip ot the needle. Any little piece of crap will stick it open. Also make sure there isnt a ring indention around it, that would mean somebody tightened it down too much at some point and damaged it.

If its clean and in good shape, go ahead and screw it back in. You might have to get new sealing washers depending on how old they are and if they come off in one piece. If the bowl is off and you can see the float, you adjust the needle till the float sits level as a starting point. If the bowl is on the car, Im sure holly has some sceintific way to set it but I just screw it in till there are just a couple threads sticking up. Just enough that the nut will able to grab the flats on the side of the valve. I like to start where I know it will be low and raise the level from there rather than setting it high and getting fuel all over the place when I try to adjust it. Now start the car and remove the site plugs on the side of the bowl to see where the level is. If fuel spills out it is too high. You want it so that the fuel level in the bowl is just at the bottom of the plug hole. Back off the jam nut a little bit at a time until the level comes up where you need it. You will need to tighten the screw as you back off the nut or fuel will squirt out. I generally like to keep a couple rags and an etinguisher handy for this operation. Im the overly cautious type but I caught one on fire many years ago when gas spilled onto the header, so there ya go.

MrKwik · Jun 27, 2005

OonDeanisS said:
the needles? How do i know what model my carb is? it has 2350 engraved in the side but it has a "holley remanufactured" sticker that says 2682. now that its apart, i see that the needle in the bowl inlet only sticks up, even when the float drops, but only sometimes, and it comes down if i tap the bowl. I think thats just cuz its dry metal.

Sorry, I missed this question. If the needle is sticking up, go ahead and replace it. As far as I know, all holly carbs use the same needle valve assembly and most autoparts stores will have some hanging on the was over by all the ricer ****.

Carb problem... is it fuel pressure?

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