borrow another carb and try that.anything is possible but i just dont see it being under carbed.if the carb was to small it would run untill it runs out of air then quit pulling.you need to tell us more about the motor.is it stock or what.you say fallin on its face,do you mean cutting out ,sputtering or just flat out bogging down and fixin to die.i still think your havin a fuel problem,not enough jet or not enough fuel to the carb.could be low float level.need more info

 

Check the simple things first, fuel filter being foremost. If you are sure your fuel pump is functioning properly, then check the carb. Assuming you have a quadrajet, the secondaries might be running out of gas. There is a small passage inside the carb that feeds fuel to them, it may be plugged. That will cause the car to go great at first then run out of power. If the problem is the carb and given the problems with old quadrajets, probably replace it rather than rebuild.

 

dont know much about the engine as far as i know its stock with flowtech headers.As for what i mean by fallin on its face it will drive fine but as soon as try to open all the barrels it bogs out and throws u forward in the seat.Would a bad exhaust leak make it do that??

 

bad exhuast leaks sound like chit,thats about the extent of that.i believe you have a fuel problem.a bad line from the tank to the pump,the pump not putting out enough pressure,you will want about 7psi on the stock motor.you said the carb had been rebuilt,how long ago.they do go bad just setting over a long length of time.the jets could be wrong,the floats could be set wrong or sticking,could be a bad accelerator pump ,not pumping enough fuel when you stand on it.the top gates on the back 2 barrels may not have enough vacuum to open them.the best thing to do is find a carb that you can barrow and put it on and see if the problems went away,if they did ,your best bet would be to get another carb

 

The carb was rebuilton this past sunday.I will check the fuel lines and the pump.Thats why I asked for a vacuum diagram for a rochester quadajet i dont know if i have all the vacuum lines hooked up or if there in the right place or not.How would i set the floats level.Thanx

 

on a quadrajet,you have to take the top off and use the paper guage they give you in a rebuild kit and bend the little tab on the float untill you get the proper measurement

 

If you think its a vacuum leak, start the car, then take a can of carb cleaner and start spraying around the carb. When you spray the leak, you'll notice a change in RPM, from the carb sucking in the cleaner.
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QuadraBog....Buy a Holley. I miss that sound of the Quadrajet sucking a basketball through a garden hose..

 

Did it do it before you changed the carb and what carb was on it before? even with the typical bog it should pick up again is the vacuum advace hooked up ?

 

the timing advance is hooked up and it holds vaccum.It was doing it before the carb was built and its the same carb that was on it when i got it! Would not enough manifold vacuum cause this?