1987 LX surging

I have less than 44k original miles on this car. A recent problem is the car will surge (slightly) in all gears and at different speeds. I thought maybe it was the fuel pressure regulator, but the car doesn't smell rich. I was thinking it may be the pump, but the car doesn't seem to loose any power when accelerating. I was also thinking it may be the carburetor, but again the car doesn't loose power even with hard acceleration. What else should I check. It happens in all gears just more subtle in the higher gears (i.e. 3rd and 4th). This is an automatic, btw.....

surging at idle or in gear driving?

When driving. Barely noticed while idling, but may be my imagination at idle too....