Then the next time it stayed higher still, not exactly racing but high enough to be uncomforable.
A bit further on and it felt like it was loosing torque then as if it was only firing on 3 cylinders.
A short while later it petered out. After ba while not running it started with a bit of a struggle.
A bit further on and it did the same thing again.
It kept doing this but at shorter intervals until eventually I called the RAC.
I had wondered if the head gasket was giving out but the RAC patrolman was aderment it would have to be down to the diesel injection pump.
Any ideas would be greatfully received!