UK Car Repair: astra 1.4ls, faulty sensor, modern cars

Question
hi i have a astra 14ls and its a superb car but somtims it just wont start as if it has no petrol but it has a full tank if i leve it for a bit it starts first time plz help me asap thanks  

Answer
This is becoming the major problem on modern cars! Does it always start cold, or is it erratic.  It sounds like an ECU problem, either a faulty sensor or a bad connection.  If so all you can do is check that all of the connections are clean and secure.  The next step is to have the fault memory, scanned.