Mark what battery you been puttin on mate as my mk6 was doing this with me not putting a ford one on. It came to a piont where my heater plug light was flashing and the van had no boost it took 3 weeks of in and out ford and after a new ecu, injector loom and countless man hrs to sort it (even though i could just turn the van off and restart it would cure it for a while) but its an 05 van and thought fuck em i want it right. Finally it got pinpointed to my dodgy non ford batt they put a new ford battery on and its been bob on ever since, if only they had done that to start with it would of saved them 2k in parts ........ man you gotta love warranty

Try a ford battery me old Pal