Here is a curious situation I have. Out of the blue, now, when I press down on the flush handle, the flapper in the tank rises up as it should, but the flushing action doesn't begin immediately - it hesitates for a few seconds, then it flushes normally and completely. It kind of sounds like trying to start a car with a bad starter. I tried a flange plunger in case there's some blockage, I tried adding water during the flush and I also pricked the small holes under the rim. It still hesitates as if it won't flush, but, as I keep the flush handle down, it does then flush normally and the tank refills normally. Could it be that I need to replace the flush valve, but I thought that would only affect the refill part of the action, not the actual flushing.