how do i go about finding what is causing the engine to misfire? should i just replace spark plugs and wires or is there a way to try and pin point the problem? it vibrates on idle but its random. i know it can also be a cylinder but i have no way to check that right now. any help. thanks

 

what year? obd? usually plugs and wires will do the trick but many other things can cause a misfire!

 

these things could cause a missfire loss of spark, the air/fuel mixture is too far out of balance to ignite, or loss of compression.