Misfire issues - 2000 Ram 1500 Van

[DodgeVanGuy]

Hi All,

I have a 2000 dodge ram 1500 van that was throwing a OBD P0305 code at me. I did a full tune-up: plugs, wires, cap, rotor, and coil pack. After tuneup, I have P0300, 306, and 308. Questions:

- Anybody have similar issues with misfire jump after tuneup? Causes?
- Would this be more likely related to my PCM or fuel injection?

I've already sunk lots of $ into getting this thing fixed, and am trying to avoid just purchasing every possible part...what would your next step be?

Thanks!

 

[dudeman2009]

Looks to me like cyl 6 and 8 are cross talking and causing the misfire. Check your spark plug wires, i'd bet those two cylinders wires are either running alongside each other or touching. Make sure none of the ignition wires are touching and if they must, make sure its as close to perpendicular as possible.

 

[DodgeVanGuy]

Thanks dudeman2009, I actually fixed this issue by cleaning the gasket and gasket seat where the plugs sit. #8 and 6 are firing just fine now. Unfortunately, the original issue that made me go for a tuneup returned: misfire in cylinder #5. Did a compression test, and get absolutely zero compression on #5. All other cylinders get regular pressure (~170), which makes me think this is an issue with valves (as opposed to piston rings). Thoughts on that, anybody? What would your next diagnostic step be?

 

[dudeman2009]

Thanks dudeman2009, I actually fixed this issue by cleaning the gasket and gasket seat where the plugs sit. #8 and 6 are firing just fine now. Unfortunately, the original issue that made me go for a tuneup returned: misfire in cylinder #5. Did a compression test, and get absolutely zero compression on #5. All other cylinders get regular pressure (~170), which makes me think this is an issue with valves (as opposed to piston rings). Thoughts on that, anybody? What would your next diagnostic step be?

pull the valve cover on that side.