Thanks for the suggestion, but I just don't have the time or the money to do it. I am still a full time student and my VR4 is my daily driver. I never thought I'd say this, but I've learnt to drive around the problem/deal with it. Don't get me wrong, it does annoy the hell out of me and I'm not giving up. I just need to pace myself, with various experiments/repairs, otherwise this problem would have driven me crazy along time ago. Plus, I can't think of anything that would be more frustrating than taking the entire motor apart, finding nothing wrong and then putting it back together...
At the moment, I'm holding out for the results of the AEM install before I proceed any further.
Markoverclock: How are things coming along with your AEM install? Any news?