Okay, I've finally sorted mine. I replaced the manifold to egr vacuum pipe!!

Now then... After checking all pipework several times and finding no splits or holes of any kind I replaced this for the pure and simple reason that I had some similar pipe in the garage laying around.

Even now I still can't see anything wrong with the original (I've yet to pressure it up), but there is absolutely no visible fault with this pipe.

The car has been fine for around 8 days now, really can't believe it. You can buy this pipe / metre length on ebay for £1.25 delivered so it's worth eliminating for ther price.

Hope this helps someone.

Daws