1997 Nissan Sentra car not running

The car just starting to run bad at a light it felt like it was gonna stall I started it about 3 times that day I was out shoping the next day it would not start when you first turn key it almost starts then nothing just keeps turning over I check if was getting gas it is I checked spark its getting spark I sprayed ether into manifold it did not start took out spark plug spraid ether did not start I can'tget it to start