OK guys......with a 383 stroker, and 3 Rochester 2jets, my "hesitation" issues are keeping me awake at night....MULTIPLE timing adjustments, mixture adjustments, have proven fruitless.....if you grab the throttle at the middle carb, and SLOWLY start to accelerate, RPM'S start to move up, BUT--real quick, the RPMS fall, is stalls and dies, Unless you milk the throttle or flat out go wide open fast.
Now, when I do the same, and keep this little "vent" above the accelerator pump open, NO MORE HESITATION and car runs great...I have no idea what this piece on top of the carb is or does! (See pics)
do I need it? does it mean when open or off, the carb is getting more air and makes it run better?
As always, your input is appreciated!
can you post the number off the side of the carb..
that is a idle vent valve..
if your carb is working properly.. it should only be open at idle.. above that and its closed..
please verify that your carb gaskets are the proper ones for your carb.. there are several options in each kit..
i don't have a 2G rochester to open right now that has that to draw out the bowl vent path..
hold a vacuum gauge over it. you should not be building vacuum in the bowl..
your bowl gasket may be blocking the internal vent tube that goes up above the venturi..
you may want to check the base gaskets also.. there have been other 2G's that created vacuum in the bowl and caused issues.. i have not had one of those in my hands.. so i was not able to spot the vacuum leak directly into the float bowl.. nor was i able to check the internal vent shown in the drawing above..
note the 3 different base gaskets in the attachment below..
great info guys! there are no numbers on these carbs....Ive looked all over them. That vent if left open, solves all my hesitation issues so far. Yes, when its on the carb, the vent is open at idle, once acceleration starts, the vent closes, but the car hesitates. If I remove this vent, car runs strong...am I hurting anything by removing this vent cover?
I should tell you ALL this started once I installed a PCV valve with an oil separator in between the PCV valve and intake vacuum port. With out it, oil blows out all the breathers, and actually pushes thru the rear intake to block gasket.....Never thought I would have that much crankcase pressure. Once the PCV valve installed, no more leaks...ugh....maybe time for an LS...
make sure that the internal vent.. this is a round tube next to the air cleaner stud that goes down into the float bowl is NOT blocked..
that is the major issue.. if the bowl vents are blocked.. there will be suction in the float bowl and issues will happen..
do you see the power valve piston on the upper side of the picture.. there is vacuum to the top of the piston bore.. so if the bore is loose.. it will create vacuum in the float bowl.. if your vent is closed.. it will screw up the air fuel ratio..
there are a bunch of different bowl gaskets.
there are a bunch of different base plate to main body gaskets..
there are even a bunch of venturi gaskets..
there are a bunch of different bases.. but i bet its all in the bowl cover..
in this image you can see part of the vacuum passage for the power piston
If you lived near me maybe I would consider using carbs rather EFI. And people say EFI is hard, tough, confusing - I disagree looking at you posts in this thread.
As usual, another great post.
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