Help!! Whats my problem?

[Old School]

I have a 74 Charger 400 with a Thermoquad. The problem appears to be that pressure is building in the carb or
something and keeping fuel from entering the carb. The car will start and idle fine all day long, just don't try to drive it
anywhere. Once the car is started you can sit and watch the fuel filter which is clear by the way, It starts half full but after
five or ten minutes it will drain itself dry and you can see just small squirts of fuel enter the filter, at times no gas will get in there
for maybe almost a minute then it will start to dribble in again. It will periodically fill up to half full then go thru the whole cycle again.
Its not vaporlock. I have run it from a 1 gallon gas can right to the carb with a electric fuel pump get the same result. when the filter
is dry if you crack the fuel line at the carb you can hear pressure escape and the filter will fill up again. I have tried three
different carbs and one is freshly rebuilt. No change. I have changed the intake gaskets and valley pan. No change. The only thing I haven't
changed is the intake itself, i will probably do that tonight. Any body have any ideas as to what can be causing this. I'm stumped.

[Charger-Bodie]

Is the float set way too low?

[Old School]

I honestly have no idea. I have three carbs they all do the exact same thing.

[firefighter3931]

Try insulating the fuel lines and insulate the base of the carb and see if that helps. It definately sounds like vapor lock to me.....if fuel gets too hot it will expand and create vapor pressure.

You might want to check to see if the vent bowls on the carb are blocked/plugged.




Ron

[Old School]

I have moved the fuel line, and the carb isn't even to hot to touch at the base. I can hold my fingers
on the carb base when this is happening. Can a cam that isn't degreed properly cause this?

[Animal]

Why do you point towards the camshaft?

Just out of curiosity , what's the vac @ idle? , not that this would cause the problem you are suggesting regarding the fuel being sucked/pumped out the carb.

[firefighter3931]

Another thing to consider is the fuel quality....today's pump gas is designed for high pressure (40 psi) fuel injection and acts funny in a low pressure envirionment (carburator).



Ron