Carb guys, please help....

EXTRPR50 said:

I have an '84 GT and just got back from a repair shop.

My problem was a horrible idle, and hesitation on acceleration. They said the power valves were good but I may need valve seats and needles?

Not familiar with those components on a carb. I notice that when I brake hard, the car wants to die out, does this have something to do with float levels?

Thanx to all who reply

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You can pick up a rebuild kit pretty cheap. why not just yank the carb off and rebuild it ?


J.

On a Holley you can replace the inlet needle and seat assemblies separately. They are under the "float adjustment screw" on top of each bowl.

Not sure that would cause your problem, suggest pull the fuel level plug with the engine idling and see if the fuel level is too high, and see it you can just adjust it. If you have not done this, it is fairly easy, but does leak gas everywhere for as long as you have the lock nut and adjustment screw loose. Suggest getting a book on the carb first.

Check your float level first before doing anything else. You want it right where it just touches the bottom of the hole on the side of the bowl so if you pushed on the side of the car maybe some fuel would slosh out. Usually when the seats go your bowls would be flooding over into the venturis and killing your car. The point of the floats is to shut off the inlet needles as the fuel level raises them. Its like a shut off switch. Well, obviously if the seals are bad it wouldnt matter if the thing was shut off or not and so the bowls would keep filling up until they overfilled into the carb which would choke the motor with gas. Check the floats and then check back with us. Also, what kind of carburetor do you have? A hesitation can be caused by being too lean or too rich. Set the floats right and set the idle mixture screws to about 2 turns out. That is a good starting point for a tune. You want a smooth idle with little or no smell of gas and with no hesitation when you blip the throttle. Mess with that until it does that. Once you get a good baseline, then you can start changing jets if need be but I dont recommend that unless your a good seat of the pants tuner or you have access to an A/F gauge.

if you mess with the idle mixture, the screws on the stock carb work backwards from a standard holley.. turning them in makes it richer, out makes it leaner.. and there are 4, they use an allen wrench... cant remember the size off hand...