93 Geo Storm- mystery starting issues

We have a '93 Storm that has been a great car but just recently started giving us problems when we try to hop back in the car to go out again. It has just over 100k mi and runs great otherwise- VERY reliable car. New coil 3 months ago and new wires, plugs, cap, etc + fuel filter less than a year ago.

It always starts in the morning and if it has not been driven for a bit, but if I have driven for 15 miles or more and stop, then try to re-start in 5-15 minutes it will crank but not fire. The 1st time it happened, I found someone to show this to and by golly- it started! The 2nd time I waited about 15 minutes, got frustrated and just took a different car(not usually available). I tried it much later and it was fine.

Personally- I am thinking vacuum of some kind.

I don’t really have a regular mechanic for this one as all it has needed were tune ups (me) and inspections at an inspection station. Any ideas Team???

Have you tried holding the pedal all the way to the floor and attempting to start it? I wonder if it might be flooding from leaky injectors. This would be a check for that. Also, check and see if you are getting spark when it won’t start.

I have tried the foot to the floor but have not tried the spare spark plug to the engine angle yet. Foot to the floor made absolutely no change.