hey guys, i recently had my car dynod, it made good power (i thought) but during the dyno runs it was breaking up a litlle bit.
My tuner said it could possibly be a Coil-pack going out.
Then a week later i noticed loud valvetrain noise, took the covers off and a Rocker arm(intake valve) was completely loose(turned to the side) and off the pushrod and valve.

..... fast forward to recently, i noticed at high rpms on the freeway, the car sounds to be missing a little.
havent checked Plugs yet, might have fowled one perhaps?
Car ideals good drives fine otherwise.....
Im afraid to use the button again if it is missfiring though....

Any suggestion on what it could be?

and if it is a bad coil, how would i find out which one....? cause it only happens at upper rpm (4500+)

 

Wow, insane barometer. How high are you there? 24 inches damn. Have you logged misfires by cylinder? Start there. Also check your grounds/ground points

 

Hmmmm: "http://en.wikipedia.org/wiki/Atmospheric_pressure" Actually, based on http://en.wikipedia.org/wiki/Atmospheric_pressure, at an altitude of 6k feet, this would be normal...

 

Yeah, we are pretty high here @ 6000+ ft, and our Density altitude is usually around 8000+

 

Log the misfire data.