Water just swirls around in the bowl of a newer American standard toilet connected to ABS 3" drainline. Drainline has one 45 before entering a “Y” and had adequate slope. When plunged once lightly, it went right down, but just swirled at further attempts with no plunging. Any ideas as to why?
Did you check the holding tank water level and flapper operation? Maybe there is not enough water entering the bowl quick enough.
Tips from Ask the Builder.
This might help.
http://www.askthebuilder.com/B332_Toilet_Repair_Instructions_for_10_Common_Problems_.shtml
Marcel 
One thing I’ve found that could cause this is the toilet has too much sealant (wax or putty). When you plunge it pushes through, but the problem is still there. Wax is often used and people think (Yes even plumbers) that the more the better, they even use the extra tall wax rings. It makes a 3" + hole into a 2" or sometimes less.
Check to make sure there is enough water first (easiest). Then go for the off the wall casuses.
Thanks, guys. Yes, there’s plenty of water in the tank and the flapper stays up long enough. I was thinking constricted flow somehow and I like Jack’s wax ring suggestion. It is a newer installation and that may be the problem.
Wallace,
Pour about two gallons of water into the bowl and see if it will flush normally without using the flush tank.
If is does there is a restriction in between the flush tank and the bowl.
Depending on the type, it could be the flush jet at the bottom of the bowl or the rim feed holes are restricted. You can clean the jet type with a screwdriver(carefully) by doing some reaming. Check any rim feed holes with a mirror.
It’s also possible to have an object lodged in the trap portion but you usually have to remove the bowl and tip it over to find out.
Good luck.
And this type of ring (with flange) really adds to the problem…
See if a toilet rod goes through easily also.
People drop hard objects which get stuck in the porcelain all the time