[Bruce Lancaster]

"coil checked..."
When coils deteriorate, they give symptoms like this...fine when cold, then rapid deterioration with heat, fine again when cooled down. If you checked the coil for spark during the no-go time, in my experience, you will still get a spark every time the coil is grounded and released--but it will be thin, yellow spark rather than the fat, blue one you want, and does not do the job.