02 sentra 1.8 won't start

[sunlight]

I replaced the head gasket b/c of a minor #1 cyl coolant leak, but not bad. Replaced head gasket and now it will not start, when before I did all this work, it ran fine.

Fuel is in the cylinders, I am getting spark, and I rechecked placement of timing chain on cam sprockets. The starter motor turns the engine, and every once in a while it will act like it wants to fire in one cylinder, but 99.9% of the time the starter motors just turns it over and there is nothing.

I don't know what to do next. I have double checked all connections. Anyone have some guidance?

Thanks