Toilets, Sinks, Showers, Tubs and Disposals - toilet bowl not filling

If I hold the handle down till bowl is empty and noise stops, the bowl will fill up agin. If I just flush it in the regular way the bowl does not fill all the way for the next flush. I watched and the flapper comes down too quickly. There must be a way for me to adjust the flapper. Would that do it? If so, how do I do it? Thanks, Doris

The first thing to do is make sure the chain does not have excess slack and/or has too little slack for the flapper to function right.If you can't tell try adjusting it small amounts and see what happens.The chain should have just a little bit of play when the flapper is down.

If that doesn't work then replace the flapper and again make sure the chain is set right.

When you flush does enough water come into the bowl to remove the contents?(when not holding the handle down?)

yes it will flush but it is worrisome and feel I must have a plunger ready at all times. My chain seems a bit too slack but it is in the highest setting. Is there a way to adjust?

If the chain is made of small links you should be able to open them and change which one is hooked to the handle.Some version also come with a clip that can be removed and replaced on other parts of the chain.If it's ball chain then either the flush lever is designed for that and the chain can be removed and rehooked at a different point or there is a clip on it that can be moved.

If all else fails get a new flapper and try it all with that.