My buddy has a 2000 transam M6. He is misfiring on cylinder 8. He changed the plugs and wires and still has the misfire what could be causing it??

 

Your SES light isnt on by any chance is it? I've heard many PCM problems could cause this or readings it gets form O2's and such.

Timing could be off perhaps

Otherwise you could just have a bad cylinder, problem I've heard of from my dad on some older cars hes worked on.

I say plug it in to make sure nothings rong w/ the computer-check out timing tables or something on ls1edit or through another type of Tune. If they fail, rip it apart and take a gander

Just my $.02
If I am mistaken, correct me, or just acknowledge it, please do not bash. I'm just getting my knowledge on the rotating assembly built up lol and I'm speaking an educated guess from what ive seen, read and been told.

 

Check the coil, it might be on its way out.

 

How do you check if a coil is out? Can you just swap it out with a different coil that you know is working properly?

 

yup, not too hard at all