Thanks very much for the advice re rough running on 1983 4/4 after driving 10 miles, It has a cvh engine with 47,000 miles on the clock, I have tried all the suggestions, still no joy, could the ignition amplifier be faulty, how does one test it?, also it is very hot under the bonnet, the plugs tips are light brown and show a good spark. As I said it is undrivable around town and I am having to rev the engine just to stop it from cutting out at traffic lights, however the rev counter reads just over 1000rpm on cold then increases and decreases on its own very slightly.