A few things off the top of my head:

Plugs gapped, seated
Plug wires on and seated
Rotor clean, contacts good
No arching (check at night)
Fuel pressure good
MAF good

You need air, fuel and spark. You're missing one of them in one cylinder. It's not air. Fuel or spark... if you get a good fuel psi at the rail -- I think it's 45 or so, someone please chime in -- then it's spark. Just go buy a fuel pressure gauge, they're not expensive and checking it is simple. Go...

If it’s really running rough, the cylinder ID isn’t reliable. It uses the crank sendor to determine which cylinder is firing well but poor running will fool it

the mechanics have no idea whats going on with it? take it to another shop then------ sounds like to me you first and foremost need to replace the crank sensor. i think everything points to that. one thing i would like to mention is you picked up a used car correct? you mentioned that it was maintai...