Engine stalls/stumbles at part throttle

My 78 280Z.

Recently, while driving on city streets, way out in the country-burbs, my engine would just cut out with your foot on the gas, pushing just a little. So I let off the pedal, and the engine comes back., push again and it "stalls" like if it was floodded or the injuectors suddenly quit. A couple times it happened turning a corner, or when you accelerate off the light, usually just after the 1-2 gear change.

I was thinking there might be a problem with the wiper on the AFM, like water or oil on the resistive strip. or something with the flapper.

Any thoughts?

thx