Classic/Antique Car Repair: Carb Issue?, pot hole, vapor lock

Question
Roger,

I'm having a stalling problem with a 65 6 cylinder Mustang.

It happens when the car is hot after being driven 5-10 miles, and I'm just taking off from a stop light.  The longer the light, the more likely it is to happen.  

I accelerate from the stop and get the car fully in gear, then it stalls.  I usually coast at least a full car-length (usually closer to 2 car lengths) then it generally re-starts on it's own.  If I take my foot off the gas, it doesn't re-start at all.

My first thought was electrical, but right now I just don't think so.

For instance, I can pound the heck out of the accelerator while idling at a stop light and NEVER have even the slightest glitch. But as soon as I start to take-off, and drive 10-20 yards, it happens.

It only happens under very specific reproducible conditions.
  1) The car has been driving a while and is "hot"
  2) The car has been stopped, such as at a red light.
  3) When I do start to accelerate, I usually am fully in first gear, or sometimes even 2nd gear before it happens, but once it starts doing this, it ALWAYS happens at every red light until the car cools off.

If it were electrical, then I would think it should happen other times too. Such as hitting a pot-hole (Tampa's roads are full of them) or speed bump, or just driving down the street when the car is hot.

And it's not like I'm stalling it with the clutch, like I said, I'm fully in gear and accelerating when it happens.

As a side note, there is a crack in the exhaust manifold below the carb, and the manifold gasket is pretty much shot.  Could this be causing a form of vapor lock?   

I was under the impression that vapor lock usually happens between the fuel pump and the fuel tank.  

Thanks,
Lance
Lance@Robaldo.com


Answer
Lance;
Hi - I doubt it is vapor lock. if the gasket is bad - on the carb. base .replace it.I wonder how the choke is,that could be doing it. if it is closed or closing up on you. and how is the fuel filter.when was the last tune up? points, plugs, cap,rotor,etc.you should get a can of spray carb cleaner and spray the hell out of the carb. inside and out.  and check the idle.   ok