Hyundai Repair: engine misfire, engine misfire, compression check

Question
I have a 2002 accent and i get an engine misfire from time to time and then goes away. A friend of mine has a 96 elantra and he developed an engine misfire bad that will not go away. plugs,coil,wires have all been replaced. any suggestions

Answer
You'll need to do some diagnosis to determine the cause.

First, start with reading the diagnostic trouble codes.  This will enable you to determine which cylinder the misfire is on.  

Once you learn which cylinder the misfire is on, you can try switching plugs and injectors to see if the misfire moves to another cylinder.  

The primary cause of misfires is the secondary ignition system (plugs, wires, coil), but could also be caused by the fuel injectors, low fuel pressure, or an internal engine problem.  If you cannot find a problem by checking/replacing ignition components or swapping plugs and injectors, you should check your fuel pressure and do a compression check.