My 2001 Megane wont run for long?

My 51 plate Megane coupe will start and run for between 10 seconds and 5 minutes then will show two lights on the cluster before shutting down. The car sounds fine when running and revs freely. I checked the handbook and the combination of lights tells you its either a serious injection incident or coolant temperature warning. All fluid levels are ok also.
Thanks

Craig
February 2009