To make sure on what the problem could be, take your black box off for a few days, re-set the ecu, and see if you are still having problems mate.
Thing is though, it only does it when I suddenly nail the pedal down, even then it only does it once in a while. I think I have a spare black ecu some where as I know in the past I had an issue with the car turning off as soon as I touched the acc pedal.Once replaced it was fine, until now.
I can see the Vac Sensor, doesnt look to hard to get at and clean. Gotta be worth a go to.
Thanks for the idea Gord, don't have a huge amount of confidence in touching the ECU and removing the piggy back box. Im gonna need to take the charger belt off aswell aren't i?! D'oh!
Is there anyway of testing the Vac Sensor?