if you could make a diaphragm chamber from a 1 or 2 letter bottle and a balloon, with the balloon inside the bottle, and the air feeding in to the balloon, and maybe a small motor with a weighted (wheel, lever, ETC) to squeeze the bottle every so often. Then air pump would run steady and there would be a burst of presure to dive the air on the rest of the way. you might need to put a bend in the line just past the bottle (not crimp) to cause a bet of back pressure too.