Please watch the video link I attached above. ChrisFix shows you how to do all the things your asking. The best is to use a engine stethoscope.They can be picked up online or at something like harbor freight for cheap. If not you can use a long screw driver. The video shows you how.
https://www.amazon.com/Lisle-52500-M...ne+stethoscope
But I forgot this is linked to rain and water. I agree with ageoctane about following the wires. check the spark plug wires and check the ignition coils. make sure they are clean and getting power.
You can always get a spark plug tester for cheap as well. Can be picked up at harbor freight too.
https://www.amazon.com/dp/B0002STSC6...03_02_t_img_lh
