Ok, my son just got a 68 Galaxie and all of the sudden it won't stay running. When its cold it fires right up for 10 seconds, but runs very rough. I try to start it again and i have to pump the crap out of the peddle to get it to stay running. Here's what I have done in the last three months to the car
1. New Holley 625 Street Demon (air/fuel was dialed in a vacuum gauge)
2. New in line fuel filter.
3. Spark plugs
4. New vacuum lines for the carb.

Thanks in advance for any advice with this.

 

Because you have to keep pumping the gas pedal to keep it running, I would suspect it is not getting enough fuel..

After it stalls , remove the air cleaner and look inside the carburetor throat as you work the gas pedal linkage. You should see fuel squirting into the barrels. If you don't see this , could be just plain insufficient fuel provided by fuel pump or carburetor float level problem.

If carburetor was never updated to use a viton rubber needle and seat, a regular rubber point on the needle will swell from unleaded gas and produce a low float level and difficulty keeping the engine running.

I don't remember if that model Holly carb had the provision to adjust the float level. Maybe someone more familiar with that model can provide a better answer.

Make sure the vacuum lines are correct.

 

Hanky, thanks for the help. It was running great for a couple months before this happened. I do plan on changing the carb spacer it had a hair line crack I noticed when the new Holley was installed. I'll check the carb for fuel squirting like you suggested.

 

The crack you mentioned could produce the symptoms you are seeing.

 

Ok, 68 is running again. The butterfly was stuck shut. Something is going on with automatic choke. I unpluged power to it

 

The automatic choke is only supposed to get power from a part of the alternator only when the engine is running..

That choke is supposed to snap shut when the engine is cold and one of the fine tuning adjustments is to adjust the choke pull off to open the choke enough so the engine runs smoothly until the choke is fully open. If you look closely at the black choke cover, there are index marks to approx where the choke should close fully when the gas pedal is operated and the choke is allowed to set. . Immediately after start up,the choke pull off vacuum assy should open the choke enough to allow smooth operation of the engine..With the engine cold, and not running the choke should be closed.

If you altered the closed choke setting , you could have difficulty getting the engine started when the engine is cold.