Engine rides rough during some hard accelerating

[Finster]

When I accelerate hard the car bucks and wants to stall out until the point where I let off the gas. I checked the accelerator pump and it looked to be fine. Any ideas what else it could be.

So to be clear - when I accelerate hard the car bucks and wants to stall. After the engine has been running for a half hour it doesn't do it.
Thanks in advance.

[goob]

Have you tried any E-10 killer? Gas nowadays is junk! When you go to NAPA to get your new oil filter, etc., pick up some fuel additive. Or, let the car run for 1/2 an hour before you romp on it!

Gary.

[WILLS RESTORATIONS]

Your problem is most likely due to choke adjustment. If the choke is not closing properly, the engine starves for fuel until it is fully warmed up. When the engine is cold, pump the accelerator 1 time for the choke to set. The choke butterfly should be loosely closed or just slightly open. If it is not, loosen the 3 screws holding the choke cap, then rotate the cap until it is correct. This should correct your problem. You can fine tune the cap to then get the best performance both cold and hot. Hope this helps.
Bill

[smcwilliams]

Wills is correct. Adjust the automatic choke to stay further closed to richen the A/F mixture. Make sure that when the engine is warm the choke is completely open.

Steve