76 NYB stalls

[Mark Kevin Weaver]

Looking for suggested areas to look at curing my 76 NYB stalling.
She runs fine for about 2 miles then struggles and finally stalls. Wait for a while and she's good for about 2 miles and does the same thing.
Thought it was maybe a clogged fuel filter starving her, so I replaced it. Same result.
This started after I had her out on the highway running over 70mph, she hasn't been the same since.
Always starts cold.
Ideas?
Thanks for any suggestions.

 

[Justin Plant]

dry rotted rubber lines sucking air at the gas tank or fuel pump?

 

[John FatFab]

Also, check if the gas cap vent hole is blocked.

 

[65Port]

Choke staying on? Check for binding linkage or for adjustment etc..

 

[Big_John]

Fuel pump pushrod or fuel pump is my bet, but it also could be ignition related. Bad coil or bad pickup in the distributor can do that. Possibly ECU box too.

Check the fuel by disconnecting the fuel line at the carb and sticking a piece of hose on the end. Also disconnect the coil wire so the engine doesn't start. Route that hose into a soda bottle and crank the engine over. You should see a good stream of gas into the bottle.

Check for spark the next time it happens.