Kind of a really weird carburetor question. I have a 3840S Carter on my 57 Cadillac. Just got the car runs fine at idle or under freeway load put your foot down and the thing just cuts out all power. So easy fix normally something jammed up. Car has been sitting for a few years now. Thing has been sitting in the sonicator for the last couple hours and got all the***** out like you do, used some light rubbing to clean out the the metering rods and one side of the carbs the secondary ventri's are jammed completely full of dirt. Everything just needed a real fine going through. But having never rebuilt a AFB before there is what I would call a check valve under/side the accelerator pump. The ball does not move at least any way that I can see, when I push down on the accelerator pump gas comes out that check valve back into the main reserve with the floats. A little bit comes out the accelerator pump circuit but like 1/5th what I would expect for a 365. I am****uming that thing needs to be replaced or is it supposed to do this. If I plug it up then good stream out of the circuit. If I had to take a guess it was put there for cold starts to let fuel in to the circuit when the gas is not high enough in the bowl to get to the acceleration circuit, or to let hot air bleed out of the system. Its not in the big rebuild kit. I have a plug that will fit right in. Part looks like this, bout 5$ through the internet but nobody local has one. [ Also on the venturi's the gaskets provided are in no way close to matching the holes in the****embly. Can I run without these or are they 100% necessary. .
The AFB I had on a 283 did the same ...Replaced the check valve and cured the problem...As I remember it was hard to find..Not all AFB's used them ... As far as the gaskets...IMHO If Carter thought they were necessary , then I'd find & install the correct ones..
The Venturi gaskets are out of stock at the two big suppliers that I buy from. Have been for some time. Ordering the valve tonight they have two in stock. Might make them if I can find some fuel resistant gasket material around the shop. Good to hear about the valve would hate to go through the whole thing again just for that part
Keep in mind that there's likely to be both an accelerator pump inlet check valve as well as an outlet check valve. http://www.mopar.nl/wp-content/uploads/2009/08/afb.gif
Thanks man. Found a complete master kit with the ETOH resistant material this morning. Had it overnighted so I can get the car in for plates on Friday. Might have to take you up on it. If anybody finds this in the search Mikes Carburetor supply has a goodly amount of Carter and Rochester parts. Even had the check valves as a stand alone part number. I did soak the brass check valve in 12 molar HCL which I had in the lab. Stuff will eat your skin off, got the ball freed up and found out that the spring had failed. Got a bunch of pieces of it out. Glad it happened on the bench and not in the motor.
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