I have a 73 Mach 1 with a 351c in it. It will run about half a block and want to die you can pump it and it will try to run but then dies. It will then start right up. If the motor is not under load you can rev it right up and it will not miss a beat. It just when its under load when the problem happens. Today I drove it around the block twice and at the same spot it just died. I have put a new fuel pump and filter and have checked the coil. It is pumping all kinds of fuel. Any ideas what to check next?

Thanks,
Guy

 

Sounds like you might have a float level that is way too low causing you to run out of fuel. It runs at idle and without a load on it because the demand for fuel isn't as high and the low float setting can keep up with it but when you put a load on it the demand for fuel goes up and it can't keep up with it anymore.

 

I will give that a look. Strage thing about is the carb has not been taken apart in a long time. The car ran great until this happened late this summer. I got to think its a fuel problem too.

Thanks,
Guy

 

If it has the brass float in the carburetor it could have started getting fuel inside it causing it to not float anymore. Very common.