In short Paul no checks. My son Mark has the car just now. At the moment we are in trial and error mode doing the cheapest thing first. Historically the problem has been solved in the past by replacing the coil. The car has covered 2,000 miles in 20 years but had a run from Yorkshire to London recen...

Thank you Paul,
the idea of checking coil resistance when hot and cold is a good one. Do you have any advice about coil replacement? It strikes me that the coil is set up to get pretty hot because of it's position at the front of the cylinder head.
Regards
Steve / Mark

Ignition problem when engine hot. Starts perfectly well when cold. After about 20 miles will not restart until cool. No problem on long run to London (coolant temperature 70 Celsius / no overheating). Not likely to be fuel vapour lock. What would cause HT failure when hot? ?coil ?condenser ? HT lead...