Flat Top SUs bog

[Thefultz]

So I recently got a 260z last month and this problem has finally gotten to me. The infamous post emissions Flat top SUs are bogging when I lay the pedal to the metal. They will just begin to barf gasoline out the overflow valve if I start it up and rev it while the carbs are still cold.  But this especially happens up in the hills (In Alaska) and no matter how slow I start up the carbs they will bog and puke up good gasoline. All I can do is floor it till what I assume is the floats go back up. Usually all it takes is flooring it till it touches off on 5k revs. But this problem is very persistant and when I come down from the hills after the carbs go cold all they wanna do is bog for the next 5 to 10 minutes.  Now I'm just gonna guess this problem is from sticky floats and fouled up Emission carbs. (cept for all the emissions are taken off because Alaska)

[beermanpete]

It sounds like the floats or float valves are bad. Rebuild the carbs.

[Professor Threadkiller]

The flat tops have a sight glass into the float bowl that you can use to check the fuel level while the carbs are on the car. You can use the sight glass to see if that's really your problem or not before you jump right to a rebuild.

 

Also, I don't believe those carbs have anything called an "overflow valve". Have you got a pic of what you are talking about?

 

[Tony D]

The float bowl equalization tube is in the throat of the carb up front by the choke plate.

[Professor Threadkiller]

If I had to guess, those vents are what I'm thinking he's talking about as well, but there are no valves in there. Those passageways are a straight shot down into the bowl.

 

Here's hoping we can get some pics.