90 Jeepstarts and dies after releasing key to run positi

Hi,
I suspect that your problem is not the ignition switch, but the computer. I have a 90 Jeep too and a couple of years ago the car wouldn't start. Even after 60 attempts one day in traffic! Eventually it started and later my mechanic simply unplugged the computer (near the gas pedal under the dash) and plugged in a new one to see if that fixed the problem. It did. It's been fine ever since. Not a trace of the old problem. My advice is to not spend money at a dealership who will suck you dry looking for issues that don't help. Just buy a replacement computer. They're not that expensive and the labour is 5 minutes.