If you have the hdi-
Next time it cuts out turn the ignition 2 clicks if you don't hear a "buzzing sound" then it's either the brown box behind the ecu or its the fuel pump under the rear seats
Easy way to test is get a voltmeter and tap into the fuel pump plug (easy access it's PIN number 2 I believe /blue wire) if there is a current it's the fuel pump if no current it's more than likey the brown box!
Cheers
When it does cut out though bang te pump a few times (lift rear seat up take off black dust cover and whack the pump) it will then prime when you turn over again
Next time it cuts out turn the ignition 2 clicks if you don't hear a "buzzing sound" then it's either the brown box behind the ecu or its the fuel pump under the rear seats
Easy way to test is get a voltmeter and tap into the fuel pump plug (easy access it's PIN number 2 I believe /blue wire) if there is a current it's the fuel pump if no current it's more than likey the brown box!
Cheers
When it does cut out though bang te pump a few times (lift rear seat up take off black dust cover and whack the pump) it will then prime when you turn over again