random misfire

[grayghost291]

Ok i am trying to figure something out, i have a 2005 3.7 v6 6speed and ever since we got it every so often it throws a random misfire. And bout a hand full of times it says which one it is, i have since replaced all 6 coil packs plugs twice and a pcv valve with a throttle body cleaning per a shop saying this is whats causing it i did not have them do it because it would have been bout 400 bucks for that.. Here lately it is still popping the random misfire code but the last 2 or 3 times its said cyl #4 i have switched plugs and coil packs and it has came back to the same cyl #4 im not sure what els there is i can do to figure this out any ideas or suggestions would help.. thanks

 

[dodge dude94]

Have you done a compression and leak down test on the engine yet? If not, do that.

 

[grayghost291]

nope havent tried that yet.. at times it seems like when its been drove alot and it will start to shake sometimes... Im planning on friday to get into it and see if its a seal around the fuel injector letting air in or some where els. last few times its coming back as random and cyl #4 even after i changed it with a nother.. thanks for the input.