Fuel Filter Question

[ARCHINSTL]

OK -
This may sound a little naive, but bear in mind that my prior fuel filter experience was with old Britmobiles, which had an internal filter in the SU pump. My modern experience is with a plastic filter in an '88 Dodge (Mitsu) pickup, which simply cannot be monitored due to a virtually inaccessible position.
I replaced the filter upon collecting the Tercel, and again 400 miles later as a precaution. I found no crud, etc., in the filters.

However, I have noticed air bubbles at the top of the plastic dome, with the bubbles going into the tube going to the (new) fuel pump. Is this a problem? I checked it with the little flap in the tank filler pipe propped open, and there are still bubbles, which would lead me to believe that there are no leaks in any piping/tubing from the tank to the filter (all engine bay tubing has been replaced).

Could these bubbles be causing some of the hesitation/bucking under load I am still experiencing? I don't want to recite the entire litany of fixes, including readjusting the timing - still short of a carb rebuild, though. The people at AZ, Advance, and an American car mech friend have stated that these bubbles are "normal" and should not affect the hesitation... The FSM does not address this situation at all.
Has anyone else noticed this and yet their car still runs OK? This question is just because of my ignorance. Hopefully this is a normal situation.
Thanks -
Tom M.

[takza]

Could be a pinhole leak in the suction line from tank to filter....but the pump moves enough gas to recirculate a good bit back to the tank...so there ought to be plenty for the carb?

If you see a continual stream of bubbles while running...I'd say there is an air leak....maybe the pump can't push enough pressure?