'93 Sentra XE - Missing under load

I am new here; therefore, I must post in the new member forum for 48 hours. Anyhow, I am hoping someone will have some ideas.

I have a 1993 Nissan Sentra with the 1.6 liter and about 175k. Just recently, it has started to miss when accelerating or under load. It will also hesitate and stall at idle. Works fine at crusing speeds. It has gradually gotten worse. It seems to be associated with water (i.e. rain, heavy dew, or deep puddles). Once the car warmed up the missing either decreases or stops altogether. Note that it is getting worse meaning it takes longer to get it to warmup/stop.

I went for the obvious and replaced the rotor, cap and wires. They did nothing to solve the problem but the car does run and idle smoother when it warms up. I am thinking either ignition coil or maybe the fuel pump. Any thoughts? Any way to test these further to confirm the problem?

Thanks for your help.

Dax