Re: Intermittent running

[<PGAHOWELLS@domain.elided>]

Gee Graham thats a hard one!
Try this.
Something is interfering with the flow of petrol after a long run like fifty
miles.
So a prolonged exposure to a change that ocurrs when running as causing a
fault.
Probably fuel, because you changed all the ignition components.
Here is my  idea. 
It only occurs at low revs, and only when the car is really hot.
I think it is your diaphragms.
I think that when it is very hot, the diaphragms become really limp, and you
get a weak mixture just when you don't need it, accelerating from lowish revs
in top gear.
Also I suspect that the dashpot oil level is low, so the needles are whipped
out of their seats when you open the throttle with the result you get too much
air for the fuel you need.
Remedy.
Try slightly overfilling the dashpots so that the plungers resist at about
10mm instead of the 6mm in the book. If it doesn't work, its easy to lower
them again. Just remove the plunger and wipe on kitchen paper, and repeat
several times to drop the oil level.
When were the diaphragms last changed. The manual says 24000 miles. 
Let us know how you get on.
Peter Howells