After all of a week ive finally had my car diagnosed (astra mk4 1.7 dti) as of what has been the problem. it turns out its the injector pumps ECU. They've told me i need a new one.
The thing is they tell me the cheapest is around £600, i reckon i can get one cheaper. Im waiting for the part no. but i was hoping some of you guys out there might no a place that may repair them or have a cheaper one !!!