There was alot of carbon build up on the valves and some of the pockets where the buckets sit had really bad score marks in the bottom so the buckets were being compressed by the cams but due to the score marks they were sticking hence holding the valves open which resulted in overfueling and the car would not start.
This was all quite a sudden thing.
The head was taken off, I removed all the carbon from the valves and reground the valves in, the buckets were checked for burrs and the pots where the buckets go were also polished out to remove score marks and roughness, I had the head cleaned and degreased, rebuilt it, reshimmed it and it went back on.
Im totally stumped as why its happened again, which is why I was looking towards the idea oil starvation.
any surgestions or ideas Chris.