Hi there,

I had exactly the same problem a few months back.
I have changed two parts just be on the safe side.
1. fuel pump as it was making funny noise and may be overheating
2. Knock sensor - this will cut the electrics to the fuel system

Replaced both parts and the car is running fine.

If you think your fuel pump is ok, then try the knock sensor first. I can't remember how much it was but it wasn't too excessively even at dealer's price.

Hope this help.