I can't figure out this misfire issue on my 2000 acura/honda integra gsr?

So last time it was misfiring bad the misfire will not stop and i changed the spark plug on cylinder 2 even though it was brand new which was weird but after i changed it ran fine for a week, now recently i went to get a car wash and they did undercarriage and now it wants to start to missfire again. When the engine is cold it missfires but then it goes away but it has hesitation under heavy load. I'm guessing that water gets into the cylinder i don't know where i'm not losing cooland. I bought a new aftermarket distributer and bought ngk cables and oem fuel filter and air filter the only thing i have not done is change the oil. What do you guys suggest i should do.In addition i have no check engine lights and i'm running obd2 to obd1 jumper harness so i have an obd1 ecu on a ob2 car.

Every Honda made motor has the common problem with the valves getting tight. They need to be adjusted every 60,000 miles. Tight valves cause rough idle, misfires, and lack of power. After reading the last part of your post about the ECU switch I'm amazed the motor even runs! The sensors on the motor are not the same so the ECU is probably not working properly with your motor's sensors. You've got an ECU made for crankshaft sensors and you have a distributor with a built in module instead of a crankshaft sensor.