ok, i am working on a 1964 1/2 mustang 260 with a 2 bbl. i have rebuilt the carb and still haveing the same problems. it will start just fime, but idles really erratically and fall on its face if you press the gas. sometime it will also backfire up through the carb. the reason for the rebuild was the accelerator pump daiphragm was busted as well as the power valve. recently put new plugs cap and rotor button on the car too. i have new wires for the car but i am waiting to get the carb issues worked out first. any ideas would be greatly appreciated.

 

Maybe the throttle rod bushings are worn out as well ? (a common problem)

Check them 3with an unlit propane torch

Carb backfire is usually from engine being out of time

 

i will check that. i am going to check to make sure i didnt mix a plug wire up on the cap also. because the car has always been in time, and has never backfired until yesterday. i think that might be the backfiring issue.

 

some how, some way, something in the timing is out of wack