I don't know, honestly. I don't think a timing problem, no matter how bad, would cause the problem you're having but then again I do not know how the ECU would react to the timing being off even a little. But, I doubt it. I do know that electronics that act "weird' for "no good reason" are often failed (I'm a computer "tech" for the last 20 years, seen a lot of weird crap, and computer motherboards can have the same issues documented below)

I do know that capacitors fail, and when you read about what they do to ECU's here you will see why I am suggesting looking into the ECU as the root cause. http://avproecm.com/
Specifically look at this page: http://www.avproecm.com/process1.htm

I have no personal experience but I read what they have on their website and I believe these guys know what they're talking about. They're doing more than a re-cap on the boards, they're actually fixing damaged traces which goes a lot further. You might give them a shout and see if they think your symptoms match a failed ECU.