96 volvo 850 misfiring after washing engine need advice pls!!?

hi i have a 96 volvo 850 and the other day i was washing the engine i covered all needed parts.i started the car and ran it for a few mins turned off close hood and continued to wash the rest of car.i then started car again and it was idling rough and drove like it was lacking power and felt like it was the engine was misfiring .i hookd up a dignoctic tester due to check engine light being on and said the 3 cylinder misfiring, so i changed spark plugs and distrubution cap but stil no beter ,i did buy a rotor but old 1 looked fine so i left the old 1 in,is there something i sould look at .also if anyone has a wire/hose diagram i want to kno if i put the 2 hoses coming from air filter box is in right spot.im lost! and need some good advice pls !!thx