Right bit of an update on this issue, I have changed the fuel pump for a brand new one, the first thing I noticed is that the performance of the car had greatly improved I then let the car run up to near hot on the temperature gauge and not once did it cut out, I then took the car out for a drive and I noticed that it was running very lumpy but again it didn't cut out. It was like it still had a slight starvation problem. Also I took the fuel filler cap off and there was no vacuum at all. As far as the coil is concerned it is a brand new uprated coil which has been checked and is putting out the correct v along with electronic ignition which runs perfectly and doesn't miss a beat in normal circumstances unlike the old points system which was on the car. Also I took the old pump apart to see if I could see anything obvious. One thing I noticed is that there was a lot of debris inside the pump which I suppose could acount for the poor performance. Thanks again for all your suggestions. Stuart