Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem
1967 - 7027240 - Fuel Inlet Upgrade - Needle and Seat Kit
65WildCat:
I have a new problem.. After sitting for a few months or so, I went to start up the car...
The fuel bowl had dried out by this time i guess .. Mechanical fuel pump... Got it going after a bit of cranking,
Then ran great for 40 seconds or so --- Then, fuel kept overflowing the top of the carb.. A lot of it...
Pouring out everywhere it could... Obviously running real rich.... After a few more tries with the same results over a few hour
period, she finally settled down and ran correctly after that initial fuel break in period... Then I parked it for another two or three weeks
thinking that would be the end of it... Cranked her over today -- Ran smooth as ice for half a minute --
then the wonderful smell of raw fuel overflowing the carb once again.... And a lot of it...
This is kind of dangerous, and I'm not prepared for an engine fire while cruising down the road....
Or for just jumping in and starting the engine and not having to constantly check under the hood.
And for --- Piece of Mind.....
Foam Float stuck in the down position, Not rising ??? Needle stuck open after sitting and refilling the bowl ??? Accell Pump ???
Too Much Air in the Bowl ???
Stumped after such a perfect rebuild and run earlier this season... And Thanks for all Your Help Thus Far..
Cliff Ruggles:
Did you replace the float during the rebuild? The ethanol in the fuel may have ruined it, and it may have also ruined the tip on the fuel inlet needle valve?.....Cliff
65WildCat:
Darned Plug Popped out of the fuel supply hole... Stuffed it in there real good this time... Maybe I should have epoxied that in as well.... anyways, now it's a shelf spare... Got a decent 7027248 Late 67 Core.. with the screw in windowed seat... Just swaped my rebuilt base plate and should be good to go.... Will find out come spring time.... Until then.... Thanks for all your help............................. Still thinking 'bout switching the primary shaft to the 7044240 or 7044270. Just concerned about the manifold exhaust cross over not being completely sealed with the newer base plate being of a slightly different pattern, as well as the fast idle adjustment resting on the manifold mounting surface, requiring a 1/2 inch spacer.. I have searched and from what I'm finding, the spacers available don't completely cover the same manifold area as the older base plate... I suppose I could just tap and plug the exhaust cross over holes with some screw in plugs that should cure any probable exhaust leakage problems. I'm convinced I need the bigger primaries for this application. Just got to make it fit on my end.... 8)
Cliff Ruggles:
Those very early carbs can be troublesome. You are finding out why they upgraded the design in 1967.
There are no negatives from plugging off the exhaust holes in the intake. We've been plugging them off for years on Chevy and Pontiac applications.....Cliff
65WildCat:
Figured I would work my way up thru the years.... This is definitely an on going education - starting from scratch.... I'm getting a lot more confident playing with em and am really starting to like these carbs... Not to bad for a Street Book Apprentice... still not ready for any recipes yet.. but do enjoy the basics... also have noticed enough performance increases to warrant further into the subject...
In Your Book -- On Page 39 --- Picture on bottom right hand page states -- "Here is a quadrajet with the choke flap removed. In addition to not having any choke operation for cold starting, removing the components offers some additional airflow often needed for high-performance applications."
Question --- How much airflow improvement or More CFM will a 750 or 800 get by removing the choke flap? It is a rather large restriction on the primary side if not used or needed.
Merry X-Mas and Happy Holiday's ---- Jim
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