1985 K20 350 Hei no fire

[Sczahra]

I've got an 85 K20 Scottsdale with a 350 with hei. It's had an intermittent problem
Where it won't fire at all unless I play with the distributor, I've replaced the module
The rf capacitor, cap rotor and I've put dielectric grease on the connections and thermal
Compound on the module over the past few months with positive results every time I open
The cap and put it all back together. Sometimes it runs great and starts right up and sometimes after
Sitting even a day it won't start again. Getting good clean fuel with new tanks new pump and filter.
I thought i figured it out when I changed the module it started fine for a week and now it's the same
Old story, cranks with plenty of battery power but won't fire. The ignition switch was suggested, because there's some play in the cylinder but it doesn't make sense that it would crank, right?
Any help is appreciated thanks folks.

[Irish_Alley]

Make sure you're getting 12v on the red single power wire on the distributor when its acting up

[edgarollins]

There are two more possibilities on your dizzy.  Your in-cap coil may have failed, even if it checks out ok.  Happened to me.  Also check your pickup coil.  These two items are relatively troublefree, but if they have age on them, it is possible one or both of them have failed.  Good luck!

[Rattler12]

Also your cap itself may have a hairline crack in it it. If it does and gets damp,  arcing across the crack while damp will put a carbon track in the crack and it will continue to arc even when dry....

[jg1977c20]

i'd also say check the batt+ wire to the dist. - sometimes you have to remove the coil cap and push the coil connection in place so as that when  you push on the red wire it doesnt just catch and push the coil wire up - had that happen on an old pontiac once - but failing that the pick up coil inside the distributor may be going .