I hate to revive this old thread, but I thought that it may be of help to someone.

My issue has been resolved! After going through troubleshooting time after time I had this narrowed down to the EEC. I pulled the computer to check for bad caps or a burned board. I pulled the cover off and saw nothing obvious. I put it all back together and the problem is solved!

Long story short, I suspect that it was all along a grounding issue with the EEC. I had repeatedly pulled the EEC connector, so I'm pretty sure that the problem wasn't in the connector.

So if you get stumped, pull the EEC, crack it open and look around, put it back in and hope you're lucky!