Anyone good with carburetor issues?

[MtnT4R]

I've got a '73 Jeep CJ5 that is having some fuel delivery issues. Just replaced the fuel filter, but unless you prime the carb with fuel the engine wont start. The PO installed an Offenhauser intake manifold and 2bbl carb thats got no markings on it anywhere...any ideas? I'd like to try a gasket kit to get it up and running but no idea which one to search for.

It's leaking a little fuel from just underneath the fuel line attachment, so maybe thinking I just need to replace all the gaskets, but that shouldn't really be affecting fuel delivery- when you pull the throttle cable the jets don't squirt fuel into the barrels. I don't know much about carbs...so I'm taking the easy way out and asking you guys layball:

Sorry about the sideways photos I rotated them a few times but they just keep uploading the same.

 

[Ed_C]

It's been a while but lemme see....

Prime as in pouring fuel through the open butterflies or pump the pedal a few times before starting?

How's the drivability once it's started and warmed up?

 

[Oldmanb777]

It's a motorcraft 2150, if my memory is right. Could be a Holly 500. Both are pretty identical. Just a "semi controlled fuel leak". Anyway, if no squirt when you operated the throttle, then the accelerator pump is probably bad. Some got plugged up to pass new emission laws, but that just screwed it up. The accelerator pump is the linkage in font of the fuel bowl. Easy to change. Many of those used on jeeps had altitude compensating bellows on them. I don't see that in the picture, but it should have been on the back of the venturi body. Pull the top off, make sure the fuel bowl stays full and to the right level of fuel. If the fuel doesn't stay in the bowl, then the needle isn't staying shut when it should and fuel is draining out. Look for cracks in the bowl that could allow fuel to drain out overnight. I have several of those laying on the shelf somewhere in my cluttered garage.
Oh and as previously stated if your not accustomed to carbureted engines, its normal to pump the throttle a couple times to start it, especially when cold. Unlike fuel injection where you leave the throttle alone when starting.

 

[MtnT4R]

It's been a while but lemme see....

Prime as in pouring fuel through the open butterflies or pump the pedal a few times before starting?

How's the drivability once it's started and warmed up?

Sorry, yes I have to pour a little fuel through the open butterfly valve to prime the system. Once it fires up it runs great, and even turning off the engine for a minute it restarts just fine. But after 30 minutes or so the fuel apparently drains out and it wont start. I do pump the pedal to get it started, but something happened over the winter and that doesn't prime the carb anymore(it stays in a heated garage so its not out in the elements)

 

[MtnT4R]

It's a motorcraft 2150, if my memory is right. Could be a Holly 500. Both are pretty identical. Just a "semi controlled fuel leak". Anyway, if no squirt when you operated the throttle, then the accelerator pump is probably bad. Some got plugged up to pass new emission laws, but that just screwed it up. The accelerator pump is the linkage in font of the fuel bowl. Easy to change. Many of those used on jeeps had altitude compensating bellows on them. I don't see that in the picture, but it should have been on the back of the venturi body. Pull the top off, make sure the fuel bowl stays full and to the right level of fuel. If the fuel doesn't stay in the bowl, then the needle isn't staying shut when it should and fuel is draining out. Look for cracks in the bowl that could allow fuel to drain out overnight. I have several of those laying on the shelf somewhere in my cluttered garage.
Oh and as previously stated if your not accustomed to carbureted engines, its normal to pump the throttle a couple times to start it, especially when cold. Unlike fuel injection where you leave the throttle alone when starting.

Thanks! That gives me a great lead to start diagnosing. I'm pretty sure fuel is leaking out of that bowl, which would make sense because pumping the gas when the engine is cold doesn't produce fuel, but it runs great when I do get it started. I'll pull it apart today and see what I find.

 

[Oldmanb777]

Does it have a power enrichment valve under the bowl? They leak sometime too. But if no fuel is present under the carb, like on the manifold, I would suspect its leaking through the needle seat.

 

[MtnT4R]

Does it have a power enrichment valve under the bowl? They leak sometime too. But if no fuel is present under the carb, like on the manifold, I would suspect its leaking through the needle seat.

I dont think so...the bowl looks like a solid milled piece, unless it was hidden underneath the float. I filled it up with fuel and sure enough it started leaking again right on the gasket- its definitely leaking from one of the two underlined gaskets. Slow, but definitely enough to drain that bowl after letting it sit for more than half an hour. So...just need to order a gasket kit?

 

[AuSeeker]

I dont think so...the bowl looks like a solid milled piece, unless it was hidden underneath the float. I filled it up with fuel and sure enough it started leaking again right on the gasket- its definitely leaking from one of the two underlined gaskets. Slow, but definitely enough to drain that bowl after letting it sit for more than half an hour. So...just need to order a gasket kit?

Usually to get a gasket kit you need to ID the carburetor, most usually have a tag to know the exact model, but you said no numbers present.

You can however make your own gasket/s, most better auto part stores sells sheets of gasket material of various type materials and thickness, you just need to get the proper type and thickness and then use the old gasket and or sealing surface to pattern/make the new gasket.

 

[Oldmanb777]

In the picture, the top one with the linkage is the accelerator pump. The diaphragm that pumps the fuel is also the gasket.
The bump under the bowl houses the power enrichment valve. The gasket for it and the valve itself are to different parts. So you could easily make a gasket for that. The power enrichment valves occasionally come loose, and fall into that bowl/bump under the bowl. The power enrichment valves come in several different sizes, but most of the gaskets and accelerator pumps are the same for any of those motorcraft carbs.

 

[MtnT4R]

awesome thank you for the info guys. I just ordered some fel-pro gasket material for carburetors. hopefully get her running this weekend!

 

[RichinRidgewood]

There are throttle body injection systems that are plug and play. IMHO toss that into the recycle bin.

 

[Oldmanb777]

Last time I looked, those throttle body injection kits probably cost more than the jeep. I have never had any luck fixing electronics 50 miles from any help. Carbs, usually can be made to at least get you home.
I built a mega-squirt once. I never did get all the bugs worked out of the electronics with that. But it was neat.