HEI ?
check ignition module.
get tempremental as they get old and hot.
usually due to lack of good heat transfere.
anotherwords always clean old off and put fresh dielectric grease on every time the module gets taken off. replacement or even inspection.
Like a processor for your pc it'll heat up and burn out without this grease acting as a heat sinkparts store prob has single use size packets of this stuff for less than a buck.
