Toilet tank flapper

Hi all,
The flapper inside my mom-in law's toilet tank is closing right after flushing, it's not enough time for a good flush or fill the bowl up. I've changed flapper, messed with length of chain, water level inside tank,handle, and no difference.She has to hold down the handle the whole time to assure a good flush. Can't seem to fix it. Hope you guys can help. Thanx

What kind of toilet is this? Is it a newer low flow or an old full flow?

toilet is an Eljer 1.6 low flow. It was installed by contractors six months ago and already had problems earlier with tank leaking and supply line freezing up the other day.

If the toilet is a low flow, that is only 6 months old, I would venture to guess that the toilet is operating exactly how it was designed. It may just be a toilet with a poorly designed flush. Many low flow toilets, especially "contractor grade" are going to have very poor bowl wash, and poor performance. All low flow toilets, even the best ones, are going to have flappers that shut very quickly, not allowing the tank to empty. That is what keeps them to the 1.6G requirement. The very best ones just tend to have a more forceful flush that evacuates the bowl more efficiently. I would be willing to guess that you just have a poorly designed 1.6G toilet.

I agree with micp879. Sad to say, many of the well known brands from the past have not done a very good job of redesigning their toilets to really work with less water. Compounding that problem is the fact that many of these manufacturers sell builder models to Big Box stores. These are either factory seconds or with some design features omitted. You might improve the performance with a new fluidmaster fill valve and flapper, but you might have to replace the toilet to get the performance you want and should have. If it comes to that, I would urge serious consideration to the Toto line. The don't make cheap models for the Box Stores. Every model works like a toilet should,

Thanks to all. I'll try the fluidmaster. Hopefully, it will help.

The fill valve won't make a difference, but a different flapper valve might. A quick way to check that would be to just hold the handle down so that the flapper can't close. If more water helps, you'd be making a modification that may be illegal. Changing a flapper from the manufacturer's design often will affect how much water is dumped on each flush. Some toilets are just dogs. There ARE some out there that work well with a 1.6g flush and even 1.28g. It seems that going to 1.28g may be coming, and there'll be no more 1.6g. Maybe that will force people to actually do some design, since many of them didn't when they made the 1.6 models.